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2. Henry Ernest Dudeney, Amusements in Mathematics, Thomas Nelson, London, 1917. (Reprinted by Dover Publications, 1958.)
3. Henry Ernest Dudeney, Modern Puzzles and How to Solve Them, Frederick A. Stokey, New York, 1926.
4. Henry Ernest Dudeney, 536 Puzzles and Curious Problems (Martin Gardner, ed.), Scribners, New York, 1967.
5. Edward Kasner and James Newman, Mathematics and the Imagination, Simon and Schuster, New York, 1940.