Cita APA (7th ed.)

Williamson, H. F., & Smalley, O. A. (1957). Northwestern Mutual Life: A century of trusteeship. Northwestern University Press.

Cita Chicago (17th ed.)

Williamson, Harold Francis, i Orange A. Smalley. Northwestern Mutual Life: A Century of Trusteeship. Evanston, Ill: Northwestern University Press, 1957.

Cita MLA (9th ed.)

Williamson, Harold Francis, i Orange A. Smalley. Northwestern Mutual Life: A Century of Trusteeship. Northwestern University Press, 1957.