APA (7th ed.) Citation

Sumner, W. G., & Keller, A. G. (1914). The challenge of facts: And other essays. Yale University Press; [etc., etc.].

Chicago Style (17th ed.) Citation

Sumner, William Graham, and Albert Galloway Keller. The Challenge of Facts: And Other Essays. New Haven: Yale University Press; [etc., etc.], 1914.

MLA (8th ed.) Citation

Sumner, William Graham, and Albert Galloway Keller. The Challenge of Facts: And Other Essays. Yale University Press; [etc., etc.], 1914.