APA (7th ed.) Citation

Catholic Church. Pope (1922-1939 : Pius XI) & Pius XI, P. (1931). On Christian marriage: Complete official text of the recent encyclical letter of Pope Pius XI. America Press.

Chicago Style (17th ed.) Citation

Catholic Church. Pope (1922-1939 : Pius XI) and Pope Pius XI. On Christian Marriage: Complete Official Text of the Recent Encyclical Letter of Pope Pius XI. New York: America Press, 1931.

MLA (8th ed.) Citation

Catholic Church. Pope (1922-1939 : Pius XI) and Pope Pius XI. On Christian Marriage: Complete Official Text of the Recent Encyclical Letter of Pope Pius XI. America Press, 1931.