APA (7th ed.) Citation

(1933). Challenging essays in modern thought: (second series). D. Appleton-Century.

Chicago Style (17th ed.) Citation

Challenging Essays in Modern Thought: (second Series). New York: D. Appleton-Century, 1933.

MLA (9th ed.) Citation

Challenging Essays in Modern Thought: (second Series). D. Appleton-Century, 1933.

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