Cita APA (7a ed.)

Ker, W. P., & Fremantle, A. (1958). The dark ages. New American Library.

Cita Chicago Style (17a ed.)

Ker, W. P., y Anne Fremantle. The Dark Ages. New York: New American Library, 1958.

Cita MLA (9a ed.)

Ker, W. P., y Anne Fremantle. The Dark Ages. New American Library, 1958.