Loomis, Charles P.
Prentice Hall Inc., 1957
Buku Teks
Long, Norman, author
Tavistock Publication, 1980
Buku Teks
Loomis, Charles P., author
Prentice-Hall, 1957
Buku Teks
Moore, Wilbert E. (Wilbert Ellis), author
Prentice-Hall, 1967
Buku Teks
edited by Amitai Etzioni and Eva Etzi
Basic Books, 1964
Buku Teks