APA (7th ed.) Citation

Barnes, H. E. (1929). The twilight of Christianity. The Vanguard Press.

Chicago Style (17th ed.) Citation

Barnes, Harry Elmer. The Twilight of Christianity. New York: The Vanguard Press, 1929.

MLA (9th ed.) Citation

Barnes, Harry Elmer. The Twilight of Christianity. The Vanguard Press, 1929.

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