Não informado. (1967). Perspectives on Education. Columbia University, Teachers College.
Chicago-referens (17:e uppl.)Não informado. Perspectives on Education. New York: Columbia University, Teachers College, 1967.
MLA-referens (8:e uppl.)Não informado. Perspectives on Education. Columbia University, Teachers College, 1967.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.