APA (7th ed.) Citation

Widom, C. S. (1989). The cycle of violence. Science, 243, 160-166.

Chicago Style (17th ed.) Citation

Widom, Cathy Spatz. "The Cycle of Violence." Science 243 (1989): 160-166.

MLA (9th ed.) Citation

Widom, Cathy Spatz. "The Cycle of Violence." Science, vol. 243, 1989, pp. 160-166.