Levitt, Joel, author
Industrial Press, Inc., 2009
Buku Teks
Sikich, Geary W., author
McGraw-Hill, 1996
Buku Referensi
edited by Paul C. Dinsmore, Jeannette Cabanis-Brewin
American Management Association, 2006
eBooks
edited by Paul C. Dinsmore, Jeannette Cabanis-Brewin
American Management Association, 2011
eBooks
Yearsley, R.B., author
Gower Press, 1974
Buku Referensi