Cita APA (7th ed.)

Darwin, C. (1899). The origin of species by means of natural selection or the preservation of favored races in the struggle for life. D. Appleton.

Cita Chicago (17th ed.)

Darwin, Charles. The Origin of Species by Means of Natural Selection or the Preservation of Favored Races in the Struggle for Life. New York: D. Appleton, 1899.

Cita MLA (9th ed.)

Darwin, Charles. The Origin of Species by Means of Natural Selection or the Preservation of Favored Races in the Struggle for Life. D. Appleton, 1899.