APA (7th ed.) Citation

Catholic Church. Pope (1958-1963 : John XXIII) & John XXIII, P. (1960). On the missions: Encyclical letter. National Catholic Welfare Conference.

Chicago Style (17th ed.) Citation

Catholic Church. Pope (1958-1963 : John XXIII) and Pope John XXIII. On the Missions: Encyclical Letter. Washington: National Catholic Welfare Conference, 1960.

MLA (8th ed.) Citation

Catholic Church. Pope (1958-1963 : John XXIII) and Pope John XXIII. On the Missions: Encyclical Letter. National Catholic Welfare Conference, 1960.

Warning: These citations may not always be 100% accurate.