Turner, Bryan S.
Sage, 1983
Buku Teks SO
Hogan, Michael
Penguin Books, 1987
Buku Teks SO
Demerath, N. J. (Nicholas Jay), 1936-
Random House, 1969
Buku Teks SO
Mary Bryden
Routledge, 2001
Buku Teks SO
editor, James F. Fox
Archipelago Press, 1999
Buku Referensi