APA (7th ed.) Citation

Feuerbach, L., Barth, K., & Niebuhr, H. R. (1957). The Essence of Christianity. Harper & Brothers.

Chicago Style (17th ed.) Citation

Feuerbach, Ludwig, Karl Barth, and H. Richard Niebuhr. The Essence of Christianity. New York: Harper & Brothers, 1957.

MLA (9th ed.) Citation

Feuerbach, Ludwig, et al. The Essence of Christianity. Harper & Brothers, 1957.