The origin of species by means of natural selection ; The descent of man and selection in relation to sex

MLA

Darwin, Charles. The Origin of Species by Means of Natural Selection ; The Descent of Man and Selection In Relation to Sex. 6th ed. New York (N.Y.): Modern Library, 1872.

APA

Darwin, C. (1872). The origin of species by means of natural selection ; The descent of man and selection in relation to sex. 6th ed. New York (N.Y.): Modern Library.

Chicago

Darwin, Charles, The Origin of Species by Means of Natural Selection ; The Descent of Man and Selection In Relation to Sex. 6th ed. New York (N.Y.): Modern Library, 1872.