Cita APA (7a ed.)

Darwin, C. R., & Darwin, F. (1960). The life and letters of Charles Darwin: Including an autobiographical chapter (2nd printing.). Basic Books.

Cita Chicago Style (17a ed.)

Darwin, Charles Robert, y Francis Darwin. The Life and Letters of Charles Darwin: Including an Autobiographical Chapter. 2nd printing. New York: Basic Books, 1960.

Cita MLA (9a ed.)

Darwin, Charles Robert, y Francis Darwin. The Life and Letters of Charles Darwin: Including an Autobiographical Chapter. 2nd printing. Basic Books, 1960.