Kershaw, John D.
William Heinemann, 1973
Buku Teks
edited by Robert T. Ammerman and Michel Hersen
John Wiley & Sons, 1997
Buku Teks
Simeonsson, Rune J., author
Allyn and Bacon, 1986
Buku Teks
Dauer, Victor P., author
Burgess Publishing, 1975
Buku Teks
McCandless, Boyd R
Holt Reinhard and Winston, 1967
Buku Teks