Andrew Heywood, Political Ideologies: An Introduction, 6th, Basingstoke, Macmillan International Higher Education, 2017, pp. 14-17, ISBN978-1-137-60604-4, OCLC988218349.
Nancy Sue Love, Understanding Dogmas and Dreams, Second, Washington, District of Columbia, CQ Press, 2006, p. 16, ISBN978-1-4833-7111-5, OCLC893684473.
Alan Fenna, Jane Robbins e John Summers, Government Politics in Australia, Robbins, Jane., Summers, John., 10th, Melbourne, Pearson Higher Education AU, 2013, pp. 126 f, ISBN978-1-4860-0138-5, OCLC1021804010.
Bill Jones e Dennis Kavanagh, British Politics Today, Kavanagh, Dennis., 7th, Manchester, Manchester University Press, 2003, p. 259, ISBN978-0-7190-6509-5, OCLC52876930.
András Körösényi, Government and Politics in Hungary, Budapest, Hungary, Central European University Press, 1999, p. 54, ISBN963-9116-76-9, OCLC51478878.