Não informado. (1980). Principal. National Association of Elementary School Principals.
Chicago-referens (17:e uppl.)Não informado. Principal. Arlington, Va: National Association of Elementary School Principals, 1980.
MLA-referens (8:e uppl.)Não informado. Principal. National Association of Elementary School Principals, 1980.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.