1. J. E. Littlewood,A Mathematician's Miscellany (Methuen, London, 1953).
2. G. Chaitin,Algorithmic Information Theory (Cambridge University Press, Cambridge, 1987).
3. J. Ford, ?What is chaos that we should be mindful of it?? inThe New Physics, S. Capelin and P. Davis, eds. (Cambridge University, Press, Cambridge, 1987).
4. J. E. Hopcroft and J. D. Ullman,Formal Languages and Their Relation to Automata (Addison-Wesley, Massachusetts, 1969), Chap. 10.
5. R. Rucker,Mind Tools (Houghton Mifflin, Boston, 1987).