Wiarda, Howard J.
Thomson/Wadsworth, 2004
Buku Teks SO
Kaushik, Devendra
Sterling Publishers, , 1975
Buku Teks SO
Bryant, Raymond L.
Routledge, 1997
Buku Teks SO
edited by Chandra Talpade Mohanty, Ann Russo, Lourdes Torres
Indiana University Press, 1991
Buku Teks
Norbu, Dawa
Routledge, 1995
Buku Teks SO