APA (7th ed.) Citation

Darwin, C., Barrett, P. H., & Freeman, R. B. (1988). Variation of animals and plants under domestication, 1. Pickering.

Chicago Style (17th ed.) Citation

Darwin, Charles, Paul H. Barrett, and R. B. Freeman. Variation of Animals and Plants Under Domestication, 1. London: Pickering, 1988.

MLA (8th ed.) Citation

Darwin, Charles, et al. Variation of Animals and Plants Under Domestication, 1. Pickering, 1988.