Gultom, Edwin Bart, author
Fakultas Ilmu Sosial dan Ilmu Politik Universitas Indonesia, 2003
UI - Tesis (Membership)
White, Ron, author
Ziff-Davis, 1993
Buku Teks
Pressman, Roger S., author
Dorset House, 1991
Buku Teks
Gorsline, G. W., author
Prentice-Hall, 1980
Buku Teks
Tausworthe, Robert C., author
Prentice-Hall, 1977
Buku Teks