Kotler, Philip
Holt, Rinehart and Winston , 1971
Buku Teks
Cox, Eli P.
N.Y. Harper & Row c. , 1979
Buku Teks
Howard, John A.
Richard D. Irwin, 1957
Buku Teks
Anderson, Barry F.
Single Reef Press, 2002
Buku Teks
Mullins, John W.
McGraw-Hill , 2013
Buku Teks