APA (7th ed.) Citation

Cox, S. M. (1990). Policing into the 21st century. Police studies, 13(4), 168-177.

Chicago Style (17th ed.) Citation

Cox, Steven M. "Policing into the 21st Century." Police Studies 13, no. 4 (1990): 168-177.

MLA (9th ed.) Citation

Cox, Steven M. "Policing into the 21st Century." Police Studies, vol. 13, no. 4, 1990, pp. 168-177.