Sinnott-Armstrong, W. (1999). Moral Skepticism. In R. Audi (Ed.), The Cambridge Dictionary of Philosophy (pp. 589–590). New York: Cambridge University Press.

Sinnott-Armstrong, W. “Moral Skepticism.” In The Cambridge Dictionary of Philosophy, edited by R. Audi, 589–90. New York: Cambridge University Press, 1999.

Sinnott-Armstrong W. Moral Skepticism. In: Audi R, editor. The Cambridge Dictionary of Philosophy. New York: Cambridge University Press; 1999. p. 589–90.

Sinnott-Armstrong, W. “Moral Skepticism.” The Cambridge Dictionary of Philosophy, edited by R. Audi, Cambridge University Press, 1999, pp. 589–90.

Sinnott-Armstrong W. Moral Skepticism. In: Audi R, editor. The Cambridge Dictionary of Philosophy. New York: Cambridge University Press; 1999. p. 589–590.