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