Não informado. (1970). Viewpoints. Indiana University, School of Education.
Chicago-referens (17:e uppl.)Não informado. Viewpoints. Bloomington, Ind: Indiana University, School of Education, 1970.
MLA-referens (8:e uppl.)Não informado. Viewpoints. Indiana University, School of Education, 1970.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.