Catholic Church. Pope (1958-1963 : John XXIII). (1960). Encyclical letter, Princeps pastorum / of His Holiness John XXIII... concerning the Catholic missions ... Catholic Truth Society.
Chicago Style (17th ed.) CitationCatholic Church. Pope (1958-1963 : John XXIII). Encyclical Letter, Princeps Pastorum / of His Holiness John XXIII... Concerning the Catholic Missions ... London: Catholic Truth Society, 1960.
MLA (8th ed.) CitationCatholic Church. Pope (1958-1963 : John XXIII). Encyclical Letter, Princeps Pastorum / of His Holiness John XXIII... Concerning the Catholic Missions ... Catholic Truth Society, 1960.
Warning: These citations may not always be 100% accurate.