Não informado. (1969). Elements. University of Alberta, Department of Elementary Education.
Chicago-referens (17:e uppl.)Não informado. Elements. Alberta, Canada: University of Alberta, Department of Elementary Education, 1969.
MLA-referens (8:e uppl.)Não informado. Elements. University of Alberta, Department of Elementary Education, 1969.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.