Bakan, Michael B., author
McGraw-Hill, 2012
Buku Teks
Smart, Ninian
Cambridge University Press, 1989
Buku Teks
edited by Albert H. Yee
Pergamon Press, 1995
Buku Teks
Narayan, Uma, author
Routledge, 1997
Buku Teks
Ewen, David, author
Prentice Hall, 1968
Buku Referensi