Sirait, Frans Iriano
Universitas Indonesia, 1995
UI - Skripsi (Membership)
Katz, Paul
Prentice-Hall, 1981
Buku Teks
Jacquot, Raymond G.
Marcel Dekker , 1981
Buku Teks
Houpis, Constantine H.
McGraw-Hill, 1992
Buku Teks
Universitas Indonesia, 2000
UI - Skripsi (Membership)