APA (7th ed.) Citation

Darwin, C. (1990). The origin of species: By means of natural selection ; The descent of man : and selection in relation to sex (2nd ed.). Encyclopaedia Britannica.

Chicago Style (17th ed.) Citation

Darwin, Charles. The Origin of Species: By Means of Natural Selection ; The Descent of Man : And Selection in Relation to Sex. 2nd ed. Chicago: Encyclopaedia Britannica, 1990.

MLA (9th ed.) Citation

Darwin, Charles. The Origin of Species: By Means of Natural Selection ; The Descent of Man : And Selection in Relation to Sex. 2nd ed. Encyclopaedia Britannica, 1990.

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