IOS Press, 1998
Buku Teks
Northouse, Peter G., author
Prentice-Hall, 1985
Buku Referensi
edited by Shahe S. Kazarian, David R. Evans
Academic Press, 2001
Buku Teks
edited by Robert Berkow
Merck Sharp & Dohme Research Laboratories, 1987
Buku Teks
Rubenstein, David, author
Erlangga, 2007
Buku Teks