1. M. E. Rosheim, Robot Evolution: The Development of Anthrobotics (Wiley-Interscience Press, New York, 1994) pp. 27–29.
2. J. Vaucanson, Le Mecanisme du Flateur Automate (New Book Press, Paris, 1985) p. 78.
3. K. Kapek and P. Kussi, Toward the Radical Center: A Karel Capek Reader (Catbird Press, Czech, 1990) p. 416.
4. M. Shepard, How to Love your Flute (Ingram and Baker and Taylor Press, USA, 1980) p. 112.