Loss of general election: Beginning of Bethune's period in office: The Reece government lost its majority at the May 1969 general election for the House of Assembly, the Australian Labor Party winning only 17 of the 35 seats. The Liberal Party also won 17 seats, but joined with the sole elected member of the Centre Party, K O Lyons, to form a coalition government under Bethune with Lyons as Deputy Premier; see Peter J Boyce, 'Tasmania', Australian Journal of Politics and History, Australian Political Chronicle, May-August 1969, 15 (3) December 1969: 81-123 at 110-111.
Loss of general election: The withdrawal of the Centre Party member, K O Lyons, from the coalition with the Liberal Party, prompted Bethune to request a dissolution for a general election of the House of Assembly on 22 April 1972 at which the Australian Labor Party won a substantial majority of seats; see W A Townsley, 'Tasmania', Australian Journal of Politics and History, Australian Political Chronicle, January-April 1972, 18 (2) August 1972: 261-301 at 288-291.
References: Terry Newman, Tasmanian Premiers 1856-1988: A Biographical Handbook, (Hobart: Tasmanian Parliamentary Library, ); For background on politics in Tasmania during this period, see W A Townsley, Tasmania: Microcosm of the Federation or Vassal State, 1945-1983, pp 273-297, (Hobart: St David's Park Publishing, 1994), and .
For a brief survey of Bethune's career, see Max Bingham, 'Bethune, Walter Angus (1908-2004)', in Alison Alexander (editor), The Companion to Tasmanian History, p. 303, (Hobart: Centre for Tasmanian Historical Studies, University of Tasmania, 2005, ISBN 186295223X), online at: http://www.utas.edu.au/library/companion_to_tasmanian_history/
'Ministries: Names of the Members of Successive Ministries which have held Office in Tasmania since the inauguration of Responsible Government, together with the Dates of Appointment and Retirement', Journal of House of Assembly, Second Session of the Forty-Fifth Parliament of Tasmania, Anno LIII and LV Eliz II; Session 2 of the 45th Parliament, Volume 251, 2004-2006, (Hobart: Government Printer, Tasmania); Colin A Hughes, A Handbook of Australian Government and Politcs 1965-1974, (Canberra: Australian National University Press, 1977, ISBN 0708113400), and the website of the Parliament of Tasmania, http://www.parliament.tas.gov.au/