APA (7th ed.) Citation

Axelrod, R., Hammond, R., & Grafen, A. (2004). Altruism via kin-selection strategies that rely on arbitrary tags with which they coevolve.

Chicago Style (17th ed.) Citation

Axelrod, R., R. Hammond, and A. Grafen. Altruism via Kin-selection Strategies That Rely on Arbitrary Tags with Which They Coevolve. 2004.

MLA (9th ed.) Citation

Axelrod, R., et al. Altruism via Kin-selection Strategies That Rely on Arbitrary Tags with Which They Coevolve. 2004.