Cita APA (7a ed.)

Duncan, D., & Spencer, H. (2002). The life and letters of Herbert Spencer in two volumes: Volume I. University Press of the Pacific.

Cita Chicago Style (17a ed.)

Duncan, David, y Herbert Spencer. The Life and Letters of Herbert Spencer in Two Volumes: Volume I. Honolulu, Hawaii: University Press of the Pacific, 2002.

Cita MLA (9a ed.)

Duncan, David, y Herbert Spencer. The Life and Letters of Herbert Spencer in Two Volumes: Volume I. University Press of the Pacific, 2002.