[1] Thucydide, II, 15-16. [2] Plutarque, _Quest. gr._, 1. [3] Aristote, _Politique_, VIII, 5, 2. [4] Aristote, _Politique_, III, 9, 8; VI, 3, 8. [5] Aristote, _Politique_, VIII, 5, 10. [6] Diodore, VIII, 5. Thucydide, VIII, 21. Hérodote, VII, 155.