Stephen N. Elliot [and others]
McGraw-Hill, 2000
Buku Teks
Mager, Robert F.
Fearon, 1968
Buku Teks
Lefrancois, Guy R.
Wodsworth publications , 1985
Buku Teks
Ormrod, Jeanne Ellis
Prentice-Hall, 2003
Buku Teks
Ormrod, Jeanne Ellis
Charles E. Merrill, 2000
Buku Teks