edited by Thomas Christiano and John Christman
John Wiley & Sons, 2007
Buku Teks
Paramitha Wardhani
Fakultas Ilmu Pengetahuan dan Budaya Universitas Indonesia, 2014
UI - Skripsi Membership
edited by Robert E. Goodin and Philip Pettit
Oxford Blackwell Publishers 1997,
Buku Teks
Djohan Rady
Fakultas Ilmu Pengetahuan Budaya Universitas Indonesia, 2012
UI - Skripsi Open
Stokes, Windy
Poloty Press, 2005
Buku Teks