APA (7th ed.) Citation

Darwin, C. (1948). The Origin of Species: : by Means of Natural Selection. Watts.

Chicago Style (17th ed.) Citation

Darwin, Charles. The Origin of Species: : By Means of Natural Selection. London: Watts, 1948.

MLA (9th ed.) Citation

Darwin, Charles. The Origin of Species: : By Means of Natural Selection. Watts, 1948.

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