Engel, James F.
The Dryden Press , 1995
Buku Teks
Wells, William D.
John Wiley & Sons, 1996
Buku Teks
Schiffman, Leon G.
Pearson Education International, 2004
Buku Teks
Engel, James F.
Chicago Dryden Press, 1990
Buku Teks
Mowen, John C.
Macmillan, 1987
Buku Teks