Leo XIII, P. C. C. P. (1939). Rerum Novarum, Encyclical Letter of pope Leo XIII on the Condition of Labor. New York.
Chicago Style (17th ed.) CitationLeo XIII, Pope; Catholic Church. Pope. Rerum Novarum, Encyclical Letter of Pope Leo XIII on the Condition of Labor. New York, 1939.
MLA (8th ed.) CitationLeo XIII, Pope; Catholic Church. Pope. Rerum Novarum, Encyclical Letter of Pope Leo XIII on the Condition of Labor. New York, 1939.
Warning: These citations may not always be 100% accurate.