Robertson, I. (1983). What cults believe (4th ed.). Moody Press.
Dyfyniad Arddull ChicagoRobertson, Irvine. What Cults Believe. 4th ed. Chicago: Moody Press, 1983.
Dyfyniad MLARobertson, Irvine. What Cults Believe. 4th ed. Moody Press, 1983.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.