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.
Lua i Stíl Chicago (17ú heag.)Schmidt, 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.
Lua MLA (8ú heag.)Schmidt, Thomas V. A Guide to the Encyclicals of the Roman Pontiffs from Pius XII to Paul VI (1939-1978). Catholic University of America, 1981.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.