edited by John T. Neisworth
Aspen Systems Corporation, 1982
Buku Teks
Yell, Mitchell L.
Prentice-Hall, 1998
Buku Teks
Simeonsson, Rune J., author
Allyn and Bacon, 1986
Buku Teks
edited by Harold J. Burbach
Pendell, 1977
Buku Teks
Hallahan, Daniel P., author
Prentice-Hall, 1988
Buku Teks