Yip, George S.
Prentice-Hall, 1992
Buku Teks
Yip, George S.
Prentice Hall Englewood Cliffs, 1995
Buku Teks
Cook, Thomas A., author
American Management Association, 2007
eBooks
Brown, Stanley A.
Prentice Hall Canada, 1992
Buku Teks
Porter, Michael E., author
The Free Press , 1990
Buku Teks