Andrews, James R.
Elsevier Saunder, 2012
Buku Teks
edited by James R. Andrews, Gary L. Harrelson
W.B. Saunders, 1991
Buku Referensi
Scott, David L.
Probus Publishing Company, 1990
Buku Teks
Berman, Jeff
American Management Association, 2007
eBooks
Cohen, David
Routledge, 2006
Buku Teks