Schiffman, Leon G.
Prentice-Hall, 1991
Buku Teks
Schiffman, Leon G.
Prentice-Hall, 1991
Buku Teks
Mowen, John C.
Prentice-Hall, 2000
Buku Teks
Schiffman, Leon G.
Prentice Hall International, 2000
Buku Teks
Engel, James F.
The Dryden Press, 1986
Buku Teks