Chubb, Basil
Oxford University Press, 1974
Buku Teks
Deutsch, Karl W
Houghton Mifflin, 1970
Buku Teks
Linebarger, Paul Myron Anthony, 1913-1966, author
York D van Nostrand, 1954
Buku Teks
edited by Stephen K. Bailey
United States Information Agency, 1973
Buku Teks
Quigley, Harold S., author
University of Minnesota Press, 1956
Buku Teks