APA (7th ed.) Citation

Leo XIII, P. (1880). Encyclical Letter of Pope Leo XIII. on christian Marriage. Philadelphia.

Chicago Style (17th ed.) Citation

Leo XIII, Pope. Encyclical Letter of Pope Leo XIII. on Christian Marriage. Philadelphia, 1880.

MLA (8th ed.) Citation

Leo XIII, Pope. Encyclical Letter of Pope Leo XIII. on Christian Marriage. Philadelphia, 1880.

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