J. Winardi, author
RajaGrafindo Persada, 2005
Buku Teks
Rinaldi, author
Universitas Indonesia, 2003
UI - Tesis (Membership)
Manullang, M., author
Aksara Baru , 1974
Buku Teks
Flippo, Edwin B., author
Erlangga, 1996
Buku Teks
Manullang, M., author
Ghalia Indonesia, 1976
Buku Teks