APA (7th ed.) Citation

Leo XIII, P. C. C. P. (18). Leo XIII on Devotion to St. Joseph. Baltimore.

Chicago Style (17th ed.) Citation

Leo XIII, Pope; Catholic Church. Pope. Leo XIII on Devotion to St. Joseph. Baltimore, 18.

MLA (8th ed.) Citation

Leo XIII, Pope; Catholic Church. Pope. Leo XIII on Devotion to St. Joseph. Baltimore, 18.

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