APA (7th ed.) Citation

Catholic Church. Pope (1939-1958 : Pius XII), National Catholic Welfare Conference, & Pius XII, P. (1951). Sempiternus rex: Encyclical letter of Pope Pius XII on the fifteenth centenary of the Council of Chalcedo. National Catholic Welfare Conference.

Chicago Style (17th ed.) Citation

Catholic Church. Pope (1939-1958 : Pius XII), National Catholic Welfare Conference, and Pope Pius XII. Sempiternus Rex: Encyclical Letter of Pope Pius XII on the Fifteenth Centenary of the Council of Chalcedo. Washington, D.C.: National Catholic Welfare Conference, 1951.

MLA (8th ed.) Citation

Catholic Church. Pope (1939-1958 : Pius XII), et al. Sempiternus Rex: Encyclical Letter of Pope Pius XII on the Fifteenth Centenary of the Council of Chalcedo. National Catholic Welfare Conference, 1951.