APA (7th ed.) Citation

West, S., Pen, I., & Griffin, A. (2002). Cooperation and competition between relatives.

Chicago Style (17th ed.) Citation

West, SA, I. Pen, and A. Griffin. Cooperation and Competition Between Relatives. 2002.

MLA (9th ed.) Citation

West, SA, et al. Cooperation and Competition Between Relatives. 2002.