APA (7th ed.) Zitazioa

Santayana, G. (1962). The life of reason or the phases of human progress. Collier.

Chicago Style (17th ed.) Zitazioa

Santayana, George. The Life of Reason or the Phases of Human Progress. Nueva York: Collier, 1962.

MLA (9th ed.) Zitazioa

Santayana, George. The Life of Reason or the Phases of Human Progress. Collier, 1962.