APA (7th ed.) Citation

Walker, N. (1991). Why punish? Oxford Univ. Press.

Chicago Style (17th ed.) Citation

Walker, Nigel. Why Punish? Oxford [u.a.]: Oxford Univ. Press, 1991.

MLA (9th ed.) Citation

Walker, Nigel. Why Punish? Oxford Univ. Press, 1991.

Warning: These citations may not always be 100% accurate.