Παραπομπή APA

Gagne, R. M. (1962). Psychological principles in system development. Holt Rinehart and wiston.

Παραπομπή Chicago Style

Gagne, Robert M. Psychological Principles in System Development. New York: Holt Rinehart and wiston, 1962.

Παραπομπή MLA

Gagne, Robert M. Psychological Principles in System Development. Holt Rinehart and wiston, 1962.