Spragens, William C
University Press of America, 1979
Buku Teks
United Nations
United Nations, 1993
Buku Teks SO
Wicker, Tom
Times Book, 2002
Buku Teks
Koenig, Louis W.
Rinehart, 1960
Buku Teks SO
Fourwanto
Fakultas Ilmu Pengetahuan Budaya Universitas Indonesia, 2003
UI - Skripsi Membership