BERGER M L. (1978). GROUP TRAINING TECHNIQUES. GOWER.
Chicago Style aipamenaBERGER M L. GROUP TRAINING TECHNIQUES. NEW JERSEY: GOWER, 1978.
MLA aipamenaBERGER M L. GROUP TRAINING TECHNIQUES. GOWER, 1978.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.