1. Hesiod: Theogony
2. Homer, Odyssey 8. 267 ff (trans. Shewring) (Greek epic 8th cent. BC): “[Hephaestus:] ‘I am a cripple from my birth.’”
3. Orfanoudakis, N.: The bellows go to war. In: Paipetis, S.A. (ed.) Extraordinary Machines and Structures in Antiquity. Peri Technon Publ., Patras, Greece (2002)
4. Čapek, K.: Rossum’s Universal Robots. Oxford University Press, London (1927)
5. Gordon, J.E.: Structures, p. 146. Penguin Books Ltd, Harmondsworth (1978)