Balzhiser, Richard E., author
Prentice Hall of India, 1977
Buku Teks
Haberman, William L., 1922-, author
Boston: Allyn and Bacon, 1980
Buku Teks
Myers, Glen E., author
Prentice-Hall, 1989
Buku Teks
Haberman, William L., 1922-, author
Allyn and Bacon, 1980
Buku Teks
Cravalho, Ernest G., author
Pitman, 1981
Buku Teks