Ehrlich, Ann
Delmar Cengage Learning, 2012
Multimedia
Becker, Esther R.
Harper & Row, 1971
Buku Referensi
Boston: Houghton: 1993,
Buku Referensi
Stroman, James
[American Management Association;, ], 2012
eBooks
De Vries, Mary Ann
Prentice-Hall, 1991
Buku Referensi