Não informado. (1989). Adult Learning. American Association for Adult & Continuing Education.
Παραπομπή σε μορφή Chicago (17η εκδ.)Não informado. Adult Learning. Washington: American Association for Adult & Continuing Education, 1989.
Παραπομπή σε μορφή MLA (8th εκδ.)Não informado. Adult Learning. American Association for Adult & Continuing Education, 1989.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.