Porter, Michael E.
Free Press, 1985
Buku Teks
Augustin, Sally
John & Sons, Inc, 2009
Buku Teks SO
by Jeffrey Harrison, Robert E. Hoskisson, R. Duane Ireland, Michael A. Hitt
South Western Cengage Learning, 2013
Buku Teks
Bateman, Thomas S.
McGraw-Hill, 1999
Buku Teks
DK Multimedia, 1999
Multimedia