Schiffman, Leon G., author
Prentice-Hall, 1997
Buku Teks
Schiffman, Leon G., author
Pearson, 2015
Buku Teks
Schiffman, Leon G., author
Pearson Education, Inc., 2007
Buku Teks
Engel, James F., author
Chicago Dryden Press, 1990
Buku Teks
Schiffman, Leon G., author
Pearson Education International, 2004
Buku Teks