Cita APA (7th ed.)

Wilson, A. (1961). The old men at the zoo. Seeker & Warburg.

Cita Chicago (17th ed.)

Wilson, Angus. The Old Men at the Zoo. London: Seeker & Warburg, 1961.

Cita MLA (9th ed.)

Wilson, Angus. The Old Men at the Zoo. Seeker & Warburg, 1961.