National Association of Elementary School Principals (U.S.). (1980). Principal. National Association of Elementary School Principals.
Citazione stile Chigago Style (17a edizione)National Association of Elementary School Principals (U.S.). Principal. Arlington, Va.: National Association of Elementary School Principals, 1980.
Citatione MLA (9a ed.)National Association of Elementary School Principals (U.S.). Principal. National Association of Elementary School Principals, 1980.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.