Timpe, A. Dale
Elex Media Komputindo, 1993
Buku Teks
Kotler, Philip
[publisher not identified], [date of publication not identified]
Buku Teks
Buell, Victor P.
Pan Books, [date of publication not identified]
Buku Teks
Foster, Douglas
Longman, 1972
Buku Teks
Levitt, Theodore
Pan Books, 1962
Buku Teks