Não informado. (1980). Principal. National Association of Elementary School Principals.
Chicago-Zitierstil (17. Ausg.)Não informado. Principal. Arlington, Va: National Association of Elementary School Principals, 1980.
MLA-Zitierstil (8. Ausg.)Não informado. Principal. National Association of Elementary School Principals, 1980.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.