edited Carmen Blacker [and others]
Princeton University Press, 1971
Buku Teks
edited by Donald H. Shively
Princeton University Press, 1971
Buku Teks
Portune, Robert
The W.H. Anderson Company, 1971
Buku Teks
Artikel Jurnal
International Society for Educational Information
ISEI, 1987
Buku Teks