Hallahan, Daniel P., author
Allyn and Bacon, 1994
Buku Teks
edited by Robert M. Hashway
Praeger, 1990
Buku Referensi
Johns, Roe L.
Prentice-Hall, 1975
Buku Teks
National Education Association of the United States, 1964
Buku Teks
William G. ASP....[et.al] author
The Shoe String Press , 1985
Buku Teks