Schiffman, Leon G.
Prentice-Hall, 1997
Buku Teks
Schiffman, Leon G.
Pearson, 2015
Buku Teks SO
Schiffman, Leon G.
Pearson Education, Inc., 2007
Buku Teks SO
Schiffman, Leon G.
Pearson Education International, 2004
Buku Teks SO
Hoyer, Wayne D.
South Western Cengage Learning, 2012
Buku Teks SO