Cita APA (7a ed.)

Nunn, E., & Firth, C. B. (1953). The middle ages (1. publ., 15. impression.). Ginn.

Cita Chicago Style (17a ed.)

Nunn, Elsa, y Catherine B. Firth. The Middle Ages. 1. publ., 15. impression. London: Ginn, 1953.

Cita MLA (9a ed.)

Nunn, Elsa, y Catherine B. Firth. The Middle Ages. 1. publ., 15. impression. Ginn, 1953.