Sinnott-Armstrong, W. (2001). Ought’ Implies ‘Can'. In L. Becker & C. Becker (Eds.), Encyclopedia of Ethics (Vol. 2, pp. 1265–1266). London & New York: Routledge.

Sinnott-Armstrong, W. “Ought’ Implies ‘Can'.” In Encyclopedia of Ethics, edited by L. Becker and C. Becker, 2:1265–66. London & New York: Routledge, 2001.

Sinnott-Armstrong W. Ought’ Implies ‘Can'. In: Becker L, Becker C, editors. Encyclopedia of Ethics. London & New York: Routledge; 2001. p. 1265–6.

Sinnott-Armstrong, W. “Ought’ Implies ‘Can'.” Encyclopedia of Ethics, edited by L. Becker and C. Becker, vol. 2, Routledge, 2001, pp. 1265–66.

Sinnott-Armstrong W. Ought’ Implies ‘Can'. In: Becker L, Becker C, editors. Encyclopedia of Ethics. London & New York: Routledge; 2001. p. 1265–1266.