Audi, Robert, Ed. The Cambridge Dictionary of Philosophy. Cambridge: Cambridge University Press, 1997.

Kraut, Richard, Ed. The Cambridge Companion to Plato. Cambridge: Cambridge University Press, 1992.

Plato. The Last Days of Socrates. Trans. Hugh Tredennick and Harold Tarrant. Harmondsworth: Penguin Books, 1993.

Plato. Complete Works. Ed. John M. Cooper. Indianapolis: Hackett Publishing Company, 1997.