Não informado. (1972). Education. National School Public Relations Association.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Education. Washington: National School Public Relations Association, 1972.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Education. National School Public Relations Association, 1972.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.