Catholic Church. Pope (1922-1939 : Pius XI) & Treacy, G. C. Atheistic communism: Encyclical letter of His Holiness Pope Pius XI (with discussion club outline). Paulist Press.
Chicago Style (17th ed.) CitationCatholic Church. Pope (1922-1939 : Pius XI) and Gerald C. Treacy. Atheistic Communism: Encyclical Letter of His Holiness Pope Pius XI (with Discussion Club Outline). New York: Paulist Press.
MLA (8th ed.) CitationCatholic Church. Pope (1922-1939 : Pius XI) and Gerald C. Treacy. Atheistic Communism: Encyclical Letter of His Holiness Pope Pius XI (with Discussion Club Outline). Paulist Press.
Warning: These citations may not always be 100% accurate.