Marx, G. T. (1988). Undercover: Police surveillance in America. University of California Press.
Lua i Stíl Chicago (17ú heag.)Marx, Gary T. Undercover: Police Surveillance in America. Berkeley: University of California Press, 1988.
Lua MLA (9ú heag.)Marx, Gary T. Undercover: Police Surveillance in America. University of California Press, 1988.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.