APA (7th ed.) Citation

Bukowski, W. M., Newcomp, A. F., & Hartup, W. W. (1998). The company they keep: Friendships in childhood and adolescence. Cambridge University Press.

Chicago Style (17th ed.) Citation

Bukowski, William M., Andrew F. Newcomp, and Willard W. Hartup. The Company They Keep: Friendships in Childhood and Adolescence. Cambridge: Cambridge University Press, 1998.

MLA (9th ed.) Citation

Bukowski, William M., et al. The Company They Keep: Friendships in Childhood and Adolescence. Cambridge University Press, 1998.