Dyfyniad APA

International Congress of Applied Psychology Liège, International Association of Applied Psychology, & Piret, R. (1972). Actes. Proceedings. Editest.

Dyfyniad Arddull Chicago

International Congress of Applied Psychology Liège, International Association of Applied Psychology, and Roger Piret. Actes. Proceedings. Bruxelles: Editest, 1972.

Dyfyniad MLA

International Congress of Applied Psychology Liège, et al. Actes. Proceedings. Editest, 1972.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.