Cita APA (7a ed.)

Johnson, D. R. (1981). American law enforcement: A history. Forum Press.

Cita Chicago Style (17a ed.)

Johnson, David R. American Law Enforcement: A History. Saint Louis, Miss: Forum Press, 1981.

Cita MLA (8a ed.)

Johnson, David R. American Law Enforcement: A History. Forum Press, 1981.