Darwin, C. (1996). The origin of species by means of natural selection: The descent of man and selection in relation to sex (2nd, 6th print.). Encyclopædia Britannica.
Chicago Style (17th ed.) CitationDarwin, Charles. The Origin of Species by Means of Natural Selection: The Descent of Man and Selection in Relation to Sex. 2nd, 6th print. Chicago: Encyclopædia Britannica, 1996.
MLA (9th ed.) CitationDarwin, Charles. The Origin of Species by Means of Natural Selection: The Descent of Man and Selection in Relation to Sex. 2nd, 6th print. Encyclopædia Britannica, 1996.
Warning: These citations may not always be 100% accurate.