1. A. Beck, M. Bleicher, and J. Crow, Excursion into Mathematics, Worth, New York, 1969, pp. 327–339.
2. Martin Gardner, The Scientific American Book of Mathematical Puzzles and Diversions, Simon & Schuster, New York, 1959, pp. 73–83.
3. Michael J. Todd, The Computation of Fixed Points and Applications, Springer-Verlag, Berlin-New York, 1976.