DuBrin, Andrew J., author
Pearson education International, 2009
Buku Teks
Robbins, Stephen P., author
Prentice-Hall, 1988
Buku Teks
Umstot, Denis D
West, 1984
Buku Teks
Robbins, Stephen P., author
Pearson Education International, 2005
Buku Teks
Robbins, Stephen P., author
Pearson Prentice Hall, 2005
Buku Teks