Churchill, Gilbert A., author
Thomson, 2005
Buku Teks
Busch, Paul S
Richard D.Irwin, 1975
Buku Teks
Kerin, Roger A., author
The McGraw-Hill, 2003
Multimedia
Churchill, Gilbert A., author
The Dryden Press, 1995
Buku Teks
Bradley, Frank, author
John Wiley & Sons, Ltd, 2003
Buku Teks