Não informado. (1932). National Elementary Principal. National Association of Elementary School Principals.
Chicago (17e ed.) BronvermeldingNão informado. National Elementary Principal. Arlington, Va: National Association of Elementary School Principals, 1932.
MLA (8e ed.) BronvermeldingNão informado. National Elementary Principal. National Association of Elementary School Principals, 1932.
Let op: Deze citaties zijn niet altijd 100% accuraat.