Ancient Greek Skepticism: An article on skepticism in Ancient Greece from the Internet Encyclopedia of Philosophy, by Harald Thorsrud of Temple University.
Ancient Scepticism and the Contra Academicos of St. Augustine: A paper by Bernard Wills closely examines the logic of Augustine's response to ancient scepticism in his Contra Academicos.
Ancient Skepticism: From the Stanford Encyclopedia of Philosophy, by Leo Groarke. Article on the two movements in ancient philosophy, Pyrrhonism, and Academic Skepticism.
Aporetic Philosophia: A discussion of the development of Greek skepticism from Pyrrho to Sextus Empiricus. A reference provided by Aporetic World Music.
Classical Skepticism: Issues and Problems: By Peter Suber of Earlham College