George R. R. Martin (2012). “George R. R. Martin's A Game of Thrones 5-Book Boxed Set (Song of Ice and Fire Series): A Game of Thrones, A Clash of Kings, A Storm of Swords, A Feast for Crows, and and A Dance with Dragons”, p.1291, Bantam
Plato (1851). “The Works of Plato: Philebus, Charmides, Laches, Menexenus, Hippias major, Hippias minor, Ion, First Alcibiades, Second Alcibiades, Theages, The rivals, Hipparchus. Minos, Clitopho, The epistles”, p.295