Ellwood, Robert S. Jr
Wardsworth, 1980
Buku Teks
Artikel Jurnal
Halpern, Joel M., author
Prentice-Hall, 1967
Buku Teks
International Society for Educational Information, Inc., 1973
Buku Teks
Sakamoto, Taro, author
The International Society for Educational Information Press, Inc., 1975
Buku Teks