Vander Waerdt - The Socratic Movement Cornell University Press, 1 Jan 1994 ISBN 0801499038 [Retrieved 2015-04-20] ↑ J Piering - Antisthenes Internet Encyclopedia of Philosophy[Retrieved 2015-04-20] ↑ Nails, D, Socrates, The Stanford Encyclopedia of Philosophy (Spring 2014 Edition), Edward N. Zalta (ed.) - SECTION 2:1 (PARAGRAPH 2) [Retrieved 2015-3-24] ↑ CC.