Gelb, Joyce
Holt, Rinehart and Winston, 1971
Buku Teks
edited by Thomas R. Dye, Brett W. Hawkins
Charles E. Merrill, 1967
Buku Teks
Solomos, John, author
Routledge, 1995
Buku Teks
Miles, Matthew W., author
Allyn and Bacon, 1970
Buku Teks
Moore, Wilbert E. (Wilbert Ellis), author
Prentice-Hall, 1967
Buku Teks