Cortada, James W., author
McGraw-Hill, 1994
Buku Referensi
Bank, John, author
Prentice-Hall, 2000
Buku Teks
Fandy Tjiptono, author
Andi Offset, 1996
Buku Teks
Tarigan, Rostiana, author
Fakultas Ilmu Sosial dan Ilmu Politik Universitas Indonesia, 2005
UI - Tesis (Membership)
Hradesky, John L., author
McGraw-Hill, 1995
Buku Referensi