APA (7th ed.) Citation

Darwin, C. (2004). Descent of man, and selection in relation to sex. Penguin Books.

Chicago Style (17th ed.) Citation

Darwin, Charles. Descent of Man, and Selection in Relation to Sex. Penguin Books, 2004.

MLA (9th ed.) Citation

Darwin, Charles. Descent of Man, and Selection in Relation to Sex. Penguin Books, 2004.

Warning: These citations may not always be 100% accurate.