Walker, David, author
Australian National University Press, 1976
Buku Teks
Victoria : Deakin University
Majalah, Jurnal, Buletin
edited by Ray Laurence, Joanne Berry
Routledge, 1998
Buku Teks
edited by Anura Goonasekera and Youichi Ito
Pluto Press, 1999
Buku Teks
Council for Research in Values and Philosophy, 2005
Buku Teks