Παραπομπή σε μορφή APA (7η εκδ.)

Tough, A. (1979). The adult's learning projects: A fresh approach to theory and practice in adult learning (2nd ed.). Ontario Institute for Studies in Education.

Παραπομπή σε μορφή Chicago (17η εκδ.)

Tough, Allen. The Adult's Learning Projects: A Fresh Approach to Theory and Practice in Adult Learning. 2nd ed. Toronto, Ont.: Ontario Institute for Studies in Education, 1979.

Παραπομπή σε μορφή MLA (8th εκδ.)

Tough, Allen. The Adult's Learning Projects: A Fresh Approach to Theory and Practice in Adult Learning. 2nd ed. Ontario Institute for Studies in Education, 1979.