Norris, Frank
New York: Grove Press, 1956
Buku Teks
Greer, Rita
Thorsons, 1993
Buku Teks
Hadwiger, Don F., editor
Cal. Chandler Pub. , 1965
Buku Teks
Gulati, Ashok
Washington, D.C. The World Bank 1990,
Buku Teks
Coates, Hugh
Thorsons Publishers, 1980
Buku Teks