APA
Colwell, R. K., & Rangel, T. F. (2009). Hutchinson's duality: the once and future niche. Proceedings of the National Academy of Sciences, 106, 19651–19658.
Chicago/Turabian
Colwell, Robert K, and Thiago F Rangel. “Hutchinson's Duality: the Once and Future Niche.” Proceedings of the National Academy of Sciences 106 (2009): 19651–19658.
MLA
Colwell, Robert K., and Thiago F. Rangel. “Hutchinson's Duality: the Once and Future Niche.” Proceedings of the National Academy of Sciences, vol. 106, National Academy of Sciences, 2009, pp. 19651–58.