Metelka, Charles J., author
Delmar, 1990
Buku Referensi
Morrison, Alastair M., author
Delmar, 1996
Buku Teks
Cook, Roy A.
Pearson, 2014
Buku Teks
Kotler, Philip, author
Prentice-Hall, 1998
Buku Teks
Kotler, Philip, author
Pearson Education, 2014
Buku Teks