Western Australia

Narelle Miragliotta, Sarah Murray and Justin Harbord

Key terms/names

Constitution Act 1889 (WA), Constitution Acts Amendment Act 1899 (WA), Electoral Act 1907 (WA), Federation, secession, Western Australian Constitution Act 1890 (UK)

 

This chapter furnishes an overview of the political history of Western Australia (WA), explores the state’s relationship to the federation and outlines its key constitutional, political and electoral features. It is argued that while WA shares much in common with its federal counterparts, there are several areas of difference that continue to shape its relationship to the federation.

European settlement

Indigenous peoples inhabited the territory of what is now WA for many millennia before the official establishment of the Swan River Colony, in June 1829, by British legislation introduced the month prior. The British view of this land at that time has been described as: an area ‘that had been known to the Europeans longer than any other part of the continent and was the least wanted’.1 British settlement was ultimately a pre-emptive response to concerns about French colonial ambitions in the western half of the continent.

The particular circumstances that led to the colony’s founding by the British would shape its developmental arc for the first five decades of settlement. The British showed little appetite to invest in the nascent colony, which hampered WA’s economic growth for several decades and undermined the business case for self-government.2 Moreover, well into the first half of the 1880s, there was little urgency for responsible government among WA’s elites, who feared that mass enfranchisement would weaken their privileged grip over colonial society.3

When WA did attain self-government, it did so a number of decades behind the other original colonies. Self-government of the colony became effective from 21 October 1890, with the UK parliament’s enactment of the Western Australian Constitution Act 1890 (UK) to which was scheduled the Constitution Act 1889 (WA) (CA).

However, the eventual grant of self-government by the Imperial parliament was encumbered by several conditions: a nominated upper house, constitutional protections for native inhabitants of the colony in the form of the now redundant section 70, and retention of crown lands above the 26-degrees-south line of latitude in the hands of the British government. While the compromises were reluctantly agreed to by the colony, the outcome was nevertheless hailed as a triumph of ‘the cherished birthright of Englishmen’.4

Federation

The elation of achieving self-government was, however, quickly overshadowed by the inexorable march towards Federation. WA faced the spectre of having to relinquish its newfound independence before it had a chance to exercise it fully. Compounding the colony’s apprehension was the fact that almost half of its revenue was drawn from intercolonial tariffs. The new federal Constitution would make trade, commerce and intercourse among the states ‘free’, thereby undercutting an important revenue source for WA.5

WA did eventually vote to enter the federation, with the initiative obtaining nearly a 70 per cent ‘yes’ vote on 31 July 1900. However, the question was only presented to the people as a result of intervention by colonial authorities. In order to counter the recalcitrance exhibited by WA’s political elite, colonial authorities adopted a carrot and stick approach. The carrot took the form of a deal to address the colony’s financial anxieties, while the stick was the threat to annexe the colony’s lucrative goldfields.6

The state’s ambivalence towards the federation has remained a distinctive feature of its history and its identity. Some regard WA’s tentativeness as pathological, with one former state government minister arguing that one need only ‘[s]cratch a Western Australian and you find a ­secessionist underneath’.7 At various points in time, WA’s feelings of grievance have found expression in the call for secession.

The most serious of such efforts occurred in 1933, when WA, reeling from the Great Depression, voted to secede from the federation. The plebiscite obtained over 50 per cent of the electorate’s support.8 While the government of the time, led by Premier Collier, dutifully – if reluctantly – petitioned the Imperial parliament for relief, its refusal to hear the matter led to the supplication being dropped.9 It was the position of the Imperial parliament that it would be unconstitutional for the state to secede without federal parliamentary support.10

There have been intermittent calls for WA to consider its future outside of the federation. While the political class have generally been careful not to utter the ‘s(ecession)’ word, they have come close at times. In 2015, the premier warned that WA’s ‘future’ might not ‘lay with the rest of Australia in a financial or economic sense’, with the state facing its ‘Boston tea party moment’.11

WA and the federation today

It is, perhaps, overly simplistic to interpret secession rhetoric as a quirk of WA’s political culture or a provocation to extract concessions from the Commonwealth. Such claims are better understood as an ‘expression of the powerlessness felt by the residents’, who perceive themselves to be on the periphery of political power.12

Several factors conspire to fuel WA’s grievance. The first emerges from fiscal demands arising from the state’s geography and demography. WA occupies 33 per cent of the continent, covering a total area of 2.5 million square kilometres, with a population of 2.47 million people. It is the second least densely populated region in Australia, behind the Northern Territory.13 And while the majority of the population is urbanised, 23 per cent of its residents are located in regional areas, in ‘some of the least hospitable places on Earth’.14 This includes estimates of 12,000 people living in 274 remote Indigenous communities.15

WA’s nine regions are vital to the economic health of the state and the federation.16 In 2017–2018,17 for example, WA accounted for 42 per cent of Australia’s merchandise exports, the bulk of which was generated from natural resources and agricultural production derived from its regions.

However, the state’s size, population dispersion and the physical diversity of its regions generate significant governance demands. In ‘lacking economies of scale’, the regions present ‘multiple challenges, especially in terms of inadequate infrastructure provision and service delivery’,18 that are not confronted by WA’s counterparts to the same extent. The WA government must spend significantly more per capita on delivering an average level of services to ensure that all Western Australians enjoy a comparable standard of living to their counterparts across the federation.

The second factor that complicates WA’s relationship to the federation is the ‘tyranny of distance’. WA’s capital is closer to Jakarta than it is to Canberra, and it does not share a time zone with any of its federal cousins. Easement of the physical obstacles of distance from the eastern seaboard was slow to occur.19 While contemporary innovations in communication and transportation have removed the effects of geographic isolation to a great extent, the perception that remoteness equates to political invisibility endures.

Pre-Federation WA politicians were aware of the challenges that distance would present for the state’s visibility in the Commonwealth. Moreover, the usefulness of the federal parliament for channelling the state’s grievances quickly proved ineffectual. WA’s representation in the House of Representatives was, as it is today, diminutive owing to its small population, while the party politicisation of the Senate quickly extinguished its role as a genuine states’ chamber.

A third factor that challenges harmonious relations with the federation is economic differences. From its inception, the structure of the WA economy was distinct from the more populous ‘manufacturing’ eastern states. WA’s economy has depended heavily on exports, principally agricultural commodities and resources. This has meant that economic decisions that benefit the eastern economies have not always aligned with WA interests.

One of the earliest indications of how economic differences could prompt a misalignment of policy preferences between WA and the federal government occurred with the introduction of a federal tariff in 1902. While the tariff was a boon for the eastern states, it represented a grave economic liability for the import-dependent west.20

The sense of disenfranchisement has been magnified by the belief that the Commonwealth has exploited the state’s resource-rich economy without fair recompense. The consequences of WA’s booming resource economy have collided with fiscal equalisation arrangements that are slow to adjust to changes in the economic fortunes of the states.

WA’s concerns assumed particular urgency when the Commonwealth Grants Commission (CGC) recommended, in 2015, that WA’s share of Goods and Services Tax (GST) revenue be reduced from 37 per cent of the per capita average to 30 per cent. The sense of grievance was intensified when the Commonwealth sought to exploit the situation to compel WA to implement far reaching reforms in exchange for financial relief.21

However, the source of much of WA’s disgruntlement can ultimately be traced to the expansionist tendencies of the Commonwealth. Very quickly, it has been argued, the federation collapsed into an arrangement that is more ‘centralised than was ever envisaged or intended, indeed one of the most centralised of all true federations’.22

Constitutional overview

Prior to 1890, the colony was under British control, with a locally residing governor, the first being Captain James Stirling. While it had a Legislative Council of 18 men, of which six were appointed and the remainder elected, its enactments had to be reserved for Her Majesty’s pleasure, and the extent of executive power forestalled responsible government in the colony.

The enactment of the CA brought about a fully elected Legislative Assembly and, initially, an appointed Legislative Council, which also became an elected body in 1893, prior to the six-year limit allowed for by section 6 of the Act.23

Within a decade, amendments to the franchise and the Council and Assembly were proposed by the colony’s first premier, Sir John Forrest. While initially taking the form of amendments to the CA, it was eventually determined that a separate and distinct constitutional enactment should be introduced. To this day, WA retains two unconsolidated constitutional enactments: the CA and the Constitution Acts Amendment Act 1899 (WA).

A little over a century later, the state’s colonial apron strings were loosened with the passage of the Australia Acts 1986 (Cth and UK). These dual enactments meant that the British parliament no longer had legislative powers over the states, repugnant legislative restrictions were removed and the avenue of appeal from the state Supreme Courts to the Privy Council was abolished.

In 2015, the preamble to the CA was amended to ‘acknowledge the Aboriginal people as the First People of Western Australia and traditional custodians of the land’, followed by the statement that the WA parliament ‘seeks to effect a reconciliation with the Aboriginal people of Western Australia’.

Key government institutions

The Australia Acts 1986, although releasing Imperial legislative control, retained the role of the monarchy in the state governmental structure. The state governor was ‘Her Majesty’s representative’ (section 7[1]) although slight alterations were made to the governor’s office and it was set out that advice to the monarch was to be ‘tendered by the Premier’ (section 7[5]).

The governor’s role includes ceremonial, as well as constitutional, functions, such as assenting to legislation, proroguing parliament, issuing electoral writs, chairing the Executive Council and making governmental appointments.24 In almost all instances, the WA governor acts on advice, unless rare circumstances arise to justify the exercise of the governor’s reserve powers.

The present Assembly contains 59 members with a maximum four-year term, and the Council has 36 members, drawn from six electorates, with a fixed four-year term. The premier leads the party with a majority in the Assembly and presides over ministerial decisions made by the Cabinet. There can be up to 17 state ministerial positions, and one must be filled by a member of the Council.

The WA parliament has plenary legislative power to make ‘laws for the peace, order and good government’ of the state,25 including the ability to enact extra-territorial laws. While there are some express constitutional limits on its power through the terms of the Commonwealth Constitution, the High Court of Australia, since Federation, has also determined that some implied legislative limits exist. Further, the CA includes restrictive procedures that seek to make it more difficult for the parliament to enact or amend particular laws by standard legislative procedures (Bills must be passed by absolute majorities or referendum, or both). While such provisions will not always be binding on a later parliament and require a suitably authoritative source to be so, they seek to apply to Bills that, for example, abolish the Council or Assembly, alter the office of governor or seek to amend the restrictive procedures themselves.

Electoral law

WA operates under the oldest electoral legislation in Australia, with the current statute, the Electoral Act 1907 (WA), passed during the reign of Edward VII. While many of the original provisions of the primary Act remain in force, it has been significantly updated in response to changing societal and political norms (see Appendix).

The franchise

The initial entitlement to vote in elections was based on a property franchise for those electors over 21 years of age, with the result that mostly white males met the qualification. While the property qualification was extinguished for the Assembly by 1907, an indirect property privilege prevailed until 1923 in that voters with property holdings in multiple electorates were entitled to vote in each of those districts. The property franchise remained for the Council until 1962.26

Women were granted the vote in the Assembly in 1899, making WA second only to South Australia (SA) to confer women’s suffrage. It was also the first state to elect a woman to parliament: Edith Cowan in 1921. The extension of suffrage to Aboriginal people on fully equal terms was not achieved until 1962. Initially, enrolment and voting were optional for Aboriginal electors, even though voting was compulsory for non-Indigenous electors from 1936.

Fixed-term elections

Prior to the 2000s, the government had the power to call an election at any time of their choosing, provided they did not exceed the maximum length of the term of parliament. However, by 2011 a cross-party consensus that this privilege afforded the government an unfair electoral advantage had emerged, leading to calls to introduce fixed-term elections. Since this time, general elections have been held every four years on the second Saturday in March.

Electoral boundaries and ‘one vote, one value’

The challenge of balancing geography and demography when drawing electoral boundaries has been particularly contentious in WA, so much so that it was the last state to remove the zonal system, whereby country electorates averaged half the number of voters in metropolitan electorates.

The principle of ‘one vote, one value’ was eventually secured by the Gallop Labor government with the passage of the Constitution and Electoral Amendment Bill 2005 (WA). However, WA electoral law continues to make allowances for larger electorates in recognition of the challenges of representing such a broad area. A large district allowance provides for districts larger than 100,000 square kilometres to have a nominal increase in elector numbers. Furthermore, such electorates are permitted to be more than 20 per cent lower than the average district allowance, compared to all other districts, which must be within a 10 per cent tolerance.

Since 2005, the state’s electoral boundaries are determined by the three electoral distribution commissioners: a current or former Supreme Court judge (chair), the electoral commissioner and the government statistician.

Electoral systems

As is common to bicameral parliaments, WA’s two chambers are elected under different electoral systems.

At the inception of responsible government, elections for the Assembly were conducted under first-past-the-post (plurality) combined with single-member electoral districts. In 1907, plurality was replaced with optional preferential voting (OPV). In response to concerns from non-Labor parties about preference losses in three-way electoral contests, full preferential voting was adopted in 1911. This system remains in force today.

Elections for the Council occur under proportional representation using the single transferrable vote (PR-STV), introduced in 1987. The present system superseded the 1965 regime, comprised of two-person electorates with staggered six-year terms, conducted under full preferential voting.27

Campaign finance and public funding

Campaign finance restrictions were initially introduced in WA in 1904, in the form of election expenditure caps on candidates. But it was not until 1996 that a more comprehensive scheme was adopted, with requirements for an annual disclosure of donations and electoral expenditure by parties and associated entities. The current disclosure threshold for individual donations is $2,500.

Public funding of elections was introduced in 2006. Under the provisions, candidates can apply to be reimbursed for electoral expenditure they incurred if they secured more than 4 per cent of first preference votes (at $1.92713 per vote as at 1 July 2019).

Parties and the party system

The core elements of WA’s modern party system had emerged by 1914. Prior to this time, elections and parliament were largely the preserve of ‘notables’ who formed loose groupings in parliament. The formation of the Australian Labor Party (Labor) in 1902 radically altered this dynamic. Created to represent newly enfranchised workers and unionists, Labor quickly developed into a disciplined electoral party, enabling it to dominate the contest for government for much of the period until the late 1950s.28

Labor’s organisational and political successes triggered the mobilisation of the Liberal and National (formerly Country) parties. While a group claiming to represent business interests used the ‘Liberal’ label in 1911, it was not until the establishment of the federal Liberals in 1944 that the WA Liberals acquired the organisational discipline to emerge as the major non-Labor rival. For much of the period from the late 1950s until the 1980s,29 the Liberals dominated government, although, since this time, they have alternated with Labor in office. In the nine elections held since 1986, the Liberals have held government on four occasions, and Labor five times.

While the Liberals were slow to institutionalise, the Nationals had established robust organisational underpinnings by 1914. The party was able to leverage its close relationship with rural interests, along with its organisational structures, to become a competitive conservative party. However, similar to divisions of the National Party elsewhere, the WA Nationals have been under intense pressure from demographic changes, structural change to the economy, electoral reforms and competitive pressures from the Liberals.30 At various times, this has led to internal fracture and the existence of two separate rural parties in the state.31

Acrimony within the Nationals has also affected the party’s ties with the Liberals. There have been two key inflection points in the relationship between the conservative parties, the first of which was between 1978 and 1986, when the coalition disbanded. The second, and present, opened up in 2006, when the Nationals abandoned the coalition to pursue a looser post-election ‘partnership’ with the Liberals, in which they sought ministries and funding commitments in exchange for supporting the Liberals in office. While some scholars have declared the Nationals’ latest strategy a triumph,32 it is unclear whether this tactic will ultimately be sufficient to save the party from demographic forces over which it has no control.

Prior to the 1990s, the Council overwhelming favoured the election of members from the three major party groupings, and the conservative parties more particularly. Between 1911 and 1993, election of persons entirely unconnected to one of the three longstanding party groupings was a novel occurrence. However, in the seven elections held since 1993, 33 independents and non-major parties have been elected. PR-STV is credited with facilitating the election of ‘other’ electoral actors to the Council and breaking the almost exclusive monopoly held by the three oldest parties in the chamber. The WA Greens has been the most successful of the newer entrants; it elected its first member to the Council in 1993 and has managed to elect between two and five members of the Council at every election since.

Conclusions

WA’s formative historical experiences, its economy and its geography have made it a sometimes-disgruntled member of the federation. But WA has more in common, politically and culturally, with other members of the federation than it does differences. Its grievances have been fiscal, as against identity-based, with the result that outpourings of disaffection have ebbed and flowed with prevailing economic circumstances.33 These grievances aside, WA is an integral constitutive unit of the federation.

Appendix: timeline of key changes to elections in WA since 1890

1890

Creation of Legislative Assembly (LA) with four-year terms. Members of Legislative Council (LC) nominated by the governor until 1893. Plural voting with property qualification.

1893

Voting extended to male British subjects over 21 years of age. Property qualification continued. Optional enrolment.

1899

Adult suffrage. Women awarded the vote in LA.

1900

Payment of members and triennial terms.

1904

Plural voting abolished.

1907

Current Electoral Act passed. Preferential voting introduced.

1911

Full preferential voting introduced.

1919

Compulsory voting for the Assembly.

1920

Women became eligible to be MLAs.

1921

Edith Cowan elected as first woman in LA.

1922

Independent electoral distribution commissioners to determine electoral boundaries. Decisions ratified by parliament.

1936

Compulsory voting introduced for LA.

1939

First parliamentary election with compulsory voting.

1947

New distribution legislation – three commissioners, country ‘vote-weighting’ and no ratification of decisions by parliament.

1954

Ruby Hutchison elected as first woman in LC.

1962

Voluntary enrolment and voting for Indigenous people. LC franchise extended to include spouses, but property qualification remained. Women gained the vote in the LC.

1963–64

Adult franchise introduced for the LC with removal of the property qualification. Voting entitlements for both houses became identical. Enrolment and voting for the LC made compulsory.

1970

Voting age reduced to 18 years.

1975

Restrictions on clergymen standing for election were abolished.

1978

Reduction in number of members of either house now only by referendum.

1980

First Indigenous MP – Ernie Bridge – elected, later became first Indigenous minister.

1983

Joint enrolment procedure introduced for Commonwealth/state enrolment. Enrolment and voting became compulsory for Indigenous people. Australian citizenship became a requirement to enrol.

1987

Western Australian Electoral Commission established. Four-year term for MPs. Multi-member regions introduced in LC to replace provinces. LC voting changed to PR-STV.

2000

Funding and disclosure law introduced. Party registration law introduced.

2005

One vote, one value. Distributions in Electoral Act.

2006

Nomination qualifications – citizenship. Overseas voting expanded. Authorisation of online advertising.

2009

Itinerant voting introduced.

2011

Fixed election dates.

2016

Federal direct enrolment and update introduced. Internet voting for a limited cohort of electors. Early voting – removal of reasons.

References

Australian Bureau of Statistics (ABS) (2016). Regional population growth, Australia, 2016. Cat. No. 3218.0. Canberra: ABS. https://www.abs.gov.au/AUSSTATS/abs@.nsf/Lookup/3218.0Main+Features12016?OpenDocument

Besant, Christopher (1990). Two nations, two destinies: a reflection on the significance of the Western Australian secessionist movement to Australia, Canada and the British Empire. University of Western Australia Law Review 209: 226–7.

Black, David (1991). Factionalism and stability, 1911–1947. In D. Black, ed. The house on the hill. Perth: WA Parliament.

Bolton, Geoffrey (2008). Land of vision and mirage: a history of Western Australia since 1826. Perth: UWA Press.

—— (1993) The civil war we never had. Proceedings of the third conference of the Samuel Griffith Society, Fremantle, 5–6 November.

Burrell, Andrew (2015). Barnett’s ‘tea party’ revolt. The Australian, 13 April.

Committee for Economic Development (CEDA) (2016). CEDA State of the Regions series: regional development in Western Australia, June 2016. Melbourne: CEDA. https://www.ceda.com.au/publications/regional-development-in-western-australia

Curthoys, Ann, and Jeremy Martens (2013). Serious collisions: settlers, Indigenous people, and Imperial policy in Western Australia and Natal. Journal of Australian Colonial History 15: 121–44.

de Garis, Brian (1991) The first Legislative Council. In D. Black, ed. The house on the hill. Perth: WA Parliament.

Department of Jobs, Tourism, Science and Innovation (2019). Western Australia economic profile (May). Perth: Government of Western Australia.

Fenna, Alan (2015a). Federalism the loser as Hickey ransoms GST to push WA reforms. The Conversation, 14 April.

—— (2015b). Best laid plans? Intentions, design, and outcomes in Australian federalism. Paper published by Constitutional Centre of Western Australia.

Gallop, Geoff, and Lenore Laymen (1985). Western Australia. In Brian Costar and Dennis Woodward eds. Country to National: Australian rural politics and beyond. Sydney: George Allen & Unwin.

Hiller, Harry (1987). Secession in Western Australia: a continuing phenomenon? Australian Quarterly 59(2): 222. DOI: 10.2307/20635434

Laschon, Eliza (2018). The GST overhaul has been given the green light – here’s what it all means for WA. ABC News, 14 November. https://www.abc.net.au/news/2018-11-14/gst-explainer-how-will-wa-spend-its-windfall/10493500

Lecours, André, and Daniel Béland (2018). From secessionism to regionalism: the changing nature of territorial politics in Western Australia. Regional and Federal Studies 29(1): 25–44. DOI: 10.1080/13597566.2018.1443918

Letters patent relating to the Office of Governor of the State of Western Australia (1986, 14 February).

Martens, Jeremy (2016). Crown land, territorial integrity and responsible government in Western Australia. Studies in Western Australian History 30: 29–41.

Moon, Jeremy, and Campbell Sharman (2003). Western Australia. In Jeremy Moon and Campbell Sharman, eds. Australian politics and government, 183–208. Cambridge, UK: Cambridge University Press.

Murray, Sarah, and James Thomson (2013). A Western Australian constitution? Documents, difficulties and dramatis personae. University of Western Australia Law Review 36(2): 1–48.

Musgrave, Thomas (2003). The Western Australian secessionist movement. Macquarie Law Journal 3: 95–129.

Phillimore, John, and Lance McMahon (2015). Moving beyond 100 years: the ‘WA approach’ to National Party survival. Australian Journal of Politics and History 61(1): 37–52. DOI: 10.1111/ajph.12085

Phillips, Harry (2013). Electoral law in the state of Western Australia: an overview, 3rd edn. Perth: Western Australian Electoral Commission.

Regional Services Reform Unit (2016). Resilient families, strong communities: a roadmap for regional and remote Aboriginal communities. Perth: Government of Western Australia.

Sharman, Campbell (1993). Secession and federalism. Proceedings of the third conference of the Samuel Griffith Society, volume 3, Fremantle, 5–6 November.

Taylor, Paige (2015). Premier told to hold out on deals. The Australian, 14 April.

About the authors

Narelle Miragliotta is a senior lecturer in the Department of Politics and International Relations at Monash University, where she researches and teaches in the areas of Australian political institutions, comparative government and political parties.

 

Dr Sarah Murray is an associate professor of law at the University of Western Australia. She researches in the areas of constitutional law and court innovation. Dr Murray’s PhD thesis was awarded the 2011 Mollie Holman Doctoral Medal for Law by Monash University and was published as The remaking of the courts: less-adversarial practice and the constitutional role of the judiciary in Australia (2014). She is the co-author of The Constitution of the Commonwealth of Australia: history, principle and interpretation (2015) and Winterton’s Australian federal constitutional law: commentary & materials (2017), and co-edited Regulating preventive justice: principle, policy and paradox (2017).

 

Justin Harbord is the director of enrolment and community education at the Western Australian Electoral Commission. He has extensive electoral experience in the areas of operations, legislation, policy, technology, reform, communications, enrolment, education and reviews of electoral boundaries spanning more than 25 years. Justin is also a convenor of the Electoral Regulation Research Network.

1 Bolton 2008, 5.

2 Moon and Sharman 2003, 184.

3 Curthoys and Martens 2013, 130.

4 Martens 2016.

5 Musgrave 2003.

6 Musgrave 2003.

7 Quoted in Taylor 2015, 2.

8 Besant 1990.

9 Bolton 1993.

10 Besant 1990.

11 Burrell 2015.

12 Hiller 1987; Sharman 1993.

13 ABS 2016.

14 CEDA 2016, 11.

15 Regional Services Reform Unit 2016.

16 CEDA 2016, 13.

17 Department of Jobs, Tourism, Science and Innovation 2019.

18 CEDA 2016, 24.

19 Moon and Sharman 2003, 203–4.

20 Musgrave 2003, 99.

21 Fenna 2015a. In 2018, the Morrison federal government announced a 70 per cent floor in the GST dollar to begin in 2022–23, increasing to 75 per cent in 2025 (Laschon 2018).

22 Fenna 2015b.

23 Murray and Thomson 2013, 22.

24 ‘Letters patent’ 1986.

25 CA, section 2(1).

26 Phillips 2013, 3–5.

27 Phillips 2013.

28 de Garis 1991.

29 Black 1991.

30 Moon and Sharman 2003.

31 Gallop and Layman 1985.

32 Phillimore and Mahon 2015.

33 Lecours and Béland 2018.