APA (7th ed.) Citation

Sober, E., & Wilson, D. S. (1999). Unto others: The evolution and psychology of unselfish behavior (2. print.). Harvard Univ. Press.

Chicago Style (17th ed.) Citation

Sober, Elliot, and David Sloan Wilson. Unto Others: The Evolution and Psychology of Unselfish Behavior. 2. print. Cambridge, Mass: Harvard Univ. Press, 1999.

MLA (9th ed.) Citation

Sober, Elliot, and David Sloan Wilson. Unto Others: The Evolution and Psychology of Unselfish Behavior. 2. print. Harvard Univ. Press, 1999.