APA (7th ed.) Citation

Darwin, C., & Burrow, J. W. (1968). The origin of species. Penguin Books.

Chicago Style (17th ed.) Citation

Darwin, Charles, and J. W. Burrow. The Origin of Species. Harmondsworth, Middlesex: Penguin Books, 1968.

MLA (9th ed.) Citation

Darwin, Charles, and J. W. Burrow. The Origin of Species. Penguin Books, 1968.