APA (7th ed.) Citation

Catholic Church. Pope (1922-1939 : Pius XI), Treacy, G. C., & Pius XI, P. (1941). On Christian Marriage. Paulist Press.

Chicago Style (17th ed.) Citation

Catholic Church. Pope (1922-1939 : Pius XI), Gerald C. Treacy, and Pope Pius XI. On Christian Marriage. New York: Paulist Press, 1941.

MLA (8th ed.) Citation

Catholic Church. Pope (1922-1939 : Pius XI), et al. On Christian Marriage. Paulist Press, 1941.