International Textbook Company, 1968
Buku Teks
The Foundation Press, Inc., 1975
Buku Teks
Howard, Marshall C.
Englewood Clifts, 1983
Buku Teks
Garvey, George E., author
Greenwood Press, 1990
Buku Teks
Anderson, Ronald A., author
South-Western Publishing Company, 1950
Buku Teks