Irwin, T. H. (1988). Aristotle’s first principles. New York, NY: Oxford University Press.
MacNamara, J. (1999). Through the rearview mirror: Historical reflections on psychology. Cambridge, MA: 478 The Organized Mind MIT Press, p. 33.
Vogt, K. (2010). Ancient skepticism, публикация в E. N. Zalta (Ed.), The Stanford encyclopedia of philosophy (зима 2011). По данным сайта http://plato.stanford.edu/entries/skepticism-ancient.