APA (7th ed.) Zitazioa
ebrary, Inc, Ludwig, J., & Cook, P. J. (2003). Evaluating gun policy: Effects on crime and violence. Brookings Institution Press.
Chicago Style (17th ed.) Zitazioa
ebrary, Inc, Jens Ludwig, eta Philip J. Cook. Evaluating Gun Policy: Effects on Crime and Violence. Washington, D.C.: Brookings Institution Press, 2003.
MLA (9th ed.) Zitazioa
ebrary, Inc, et al. Evaluating Gun Policy: Effects on Crime and Violence. Brookings Institution Press, 2003.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.