APA (7th ed.) Citation

Comfort, M. H. (1965). Herbert Hoover: Boy engineer. Bobbs-Merrill.

Chicago Style (17th ed.) Citation

Comfort, Mildred H. Herbert Hoover: Boy Engineer. Indianapolis, New York: Bobbs-Merrill, 1965.

MLA (9th ed.) Citation

Comfort, Mildred H. Herbert Hoover: Boy Engineer. Bobbs-Merrill, 1965.