APA (7th ed.) Citation

Leo XIII, P. C. C. P. (1885). The Christian Constitution of States (Encyclical Immortale Dei). New York.

Chicago Style (17th ed.) Citation

Leo XIII, Pope; Catholic Church. Pope. The Christian Constitution of States (Encyclical Immortale Dei). New York, 1885.

MLA (8th ed.) Citation

Leo XIII, Pope; Catholic Church. Pope. The Christian Constitution of States (Encyclical Immortale Dei). New York, 1885.

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