J. Barnes, "Academy", E. Craig (ed.), Routledge Encyclopedia of Philosophy, Routledge, 1998, consultat: 13/9/2008, a http://www.rep.routledge.com/article/A001. (anglès)
M. Schofield, "Plato", a E. Craig (Ed.), Routledge Encyclopedia of Philosophy, Routledge 1998/2002, consultat el 13/9/2008 a http://www.rep.routledge.com/article/A088(anglès)