Kelley, Donald
Hardcourt Brace College Publisher, 1999
Buku Teks SO
Pittman, John
International, 1964
Buku Teks SO
Benaya Adiguna
Fakultas Ilmu Pengetahuan Budaya Universitas Indonesia, 2012
UI - Skripsi Open
edited by Klaus Gottstein
Westview Press, 1991
Buku Teks SO
Henderson, William Darryl
National Defense University Press , 1985
Buku Teks SO