Schmidt, T. V. (1981). A guide to the encyclicals of the Roman pontiffs from Pius XII to Paul VI (1939-1978). Catholic University of America.
Dyfyniad Arddull ChicagoSchmidt, Thomas V. A Guide to the Encyclicals of the Roman Pontiffs from Pius XII to Paul VI (1939-1978). Washington, D.C.: Catholic University of America, 1981.
Dyfyniad MLASchmidt, Thomas V. A Guide to the Encyclicals of the Roman Pontiffs from Pius XII to Paul VI (1939-1978). Catholic University of America, 1981.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.