Amos, Jimmy
Harper & Row , 1965
Buku Teks
edited by Herbert C. Schulberg
Human Science Press, 1979
Buku Teks
Fernandez, Judi N., 1941-, author
John Wiley & Sons, 1981
Buku Teks
Posavac, Emil J.
Prentice Hall Inc., 1980
Buku Teks
Espich, James E.,
Fearon Publishers, 1967
Buku Teks