Hallahan, Daniel P.
Allyn and Bacon, 1994
Buku Teks
Yell, Mitchell L.
Prentice-Hall, 1998
Buku Teks
edited by John T. Neisworth
Aspen Systems Corporation, 1982
Buku Teks
Telford, Charles Witt
Prentice-Hall, 1981
Buku Teks
editors, Seamus Hegarty; Mithu Alur
Sage production , 2005
Buku Teks