Smith, Daniel A.
Tax crusaders and the politics of direct democracy / Daniel A. Smith
Routledge, 1998
 Buku Teks
Bowler, Shaun
Demanding choices: opinion, voting, and direct democracy / Bowler Shaun and Donovan Todd;
The University of Michigan Press, 200
 Buku Teks
World minorities
edited by Georgina Ashworth
Quartermaine House, 1977
 Buku Teks
Minorities within minorities: equality, rights and diversity
edited by Avigail Eisenberg and Jeff Spenner-Halev
Camberidge University Press , 2005
 Buku Teks
Arblaster, Anthony
Democracy
Open University Press, 1987
 Buku Teks