Schaefer, Richard T, author
McGraw-Hill , 1989
Buku Teks
O`Brien, Robert W.
Houghton Mifflin, 1964
Buku Teks
Heinemann Educational Books , 1973
Buku Teks
edited by Lewis A. Coser, Bernard Rosenberg
Macmillan, 1964
Buku Teks
Broom, Leonard
Harper, 1981
Buku Teks