APA (7. basım) Alıntı

Sumner, W. G., & Keller, A. G. (1914). The challenge of facts, and other essays. Yale University Press.

Chicago Style (17. basım) Atıf

Sumner, William Graham, ve Albert Galloway Keller. The Challenge of Facts, and Other Essays. New Haven: Yale University Press, 1914.

MLA (9th ed.) Atıf

Sumner, William Graham, ve Albert Galloway Keller. The Challenge of Facts, and Other Essays. Yale University Press, 1914.