Buffa, Elwood S. (Elwood Spencer), author
John Wiley & Sons, 1987
Buku Teks
Hoffer, Jeffrey A., author
Prentice-Hall, 2002
Buku Teks
Dale, Ernest, author
Penguin Books, 1975
Buku Teks
Herbert, Theodore T., author
Macmillan, 1976
Buku Teks
Certo, Samuel C.
Allyn and Bacon, 1989
Buku Teks