APA (7th ed.) Citation

Hoover, H. C. (1934). The challenge to liberty. C. Scribner's sons.

Chicago Style (17th ed.) Citation

Hoover, Herbert Clark. The Challenge to Liberty. New York: C. Scribner's sons, 1934.

MLA (9th ed.) Citation

Hoover, Herbert Clark. The Challenge to Liberty. C. Scribner's sons, 1934.