APA
Pius XI, . (1931). Pius XI on Christian Marriage : the English translation. New York: Barry Vail Corporation.
Chicago
Pius XI, . 1931. Pius XI on Christian Marriage : the English translation. New York: Barry Vail Corporation.
Harvard
Pius XI, . (1931). Pius XI on Christian Marriage : the English translation. New York: Barry Vail Corporation.
MLA
Pius XI, . Pius XI on Christian Marriage : the English translation. New York: Barry Vail Corporation. 1931.
