Benson, Tedd, author
CT Taunton Press, 1999
Buku Teks
Eble, Kenneth E., author
Jossey-Bass, 1979
Buku Teks
McGraw-Hill, 1990
Buku Teks
Edited by Patrik O`Brian Holt; Noel Williams
Kluwer Academic Publishers , 1992
Buku Teks
edited by Arnold McMilin
Macmillan, 1991
Buku Teks