Curran, Daniel J., author
Allyn & Bacon, 1987
Buku Teks
Katona, George
McGraw-Hill , 1964
Buku Teks
edted by Joseph S. Roucek
Greenwood Press , 1978
Buku Teks
Hodgson, Godfrey
Vintage Books, 1976
Buku Teks
Carlson, John E., author
McGraw-Hill, 1981
Buku Teks