Sylvia, Ronald D.
Harcourt College Publisher, 2002
Buku Teks
Sylvia, Ronald D., author
Harcourt College Publisher, 2002
Buku Teks
Cayer, N. Joseph, author
Thomson wadsworth, 2004
Buku Teks
Nigro, Felix A., author
Holt, Rinehart and Winston , 1959
Buku Teks
edited by Steven W. Hays, Richard C. Kearney
Prentice-Hall, 1990
Buku Teks