Corey, M. S. C. a. G. Becoming a helper. Brooks/Cole.
Dyfyniad Arddull ChicagoCorey, Marianne Schneider Corey and Gerald. Becoming a Helper. Brooks/Cole.
Dyfyniad MLACorey, Marianne Schneider Corey and Gerald. Becoming a Helper. Brooks/Cole.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.