Ryan, William T
Principles of marketing/ by William Ryan
Richard D. Irwin, 1980
 Buku Teks
Ryan, William T.
Personel learning aid for principles of marketing / William T. Ryan; Roger H. hermanson
Dew Jones Irwin, 1980
 Buku Teks SO
Ryan, William T.
Programmed learning ald for principles of marketing / William T. Ryan, Roger H. Hermanson
Learning System Company, 1971
 Buku Teks SO
Davis, Judy
A Guide to web marketing
Crest, 2001
 Buku Teks
Ho, Yin Wong
Building a marketing plan : a complete guide
Business Expert Press, 2011
 Buku Teks