Cita APA (7a ed.)

Santayana, G., & Lachs, J. (1967). Animal faith and spiritual life. Appleton-Century-Crofts.

Cita Chicago Style (17a ed.)

Santayana, George, y John Lachs. Animal Faith and Spiritual Life. New York: Appleton-Century-Crofts, 1967.

Cita MLA (9a ed.)

Santayana, George, y John Lachs. Animal Faith and Spiritual Life. Appleton-Century-Crofts, 1967.