1. Cremona, John E.Algorithms for Modular Elliptic Curves, Cambridge University Press, Cambridge, 1992.
2. Dickson, Leonard E.History of the Theory of Numbers, volume 2, Chelsea, 1952.
3. Gale, DavidMathematical Intelligencer, volume 13, number 1, Springer, New York, 1991.
4. Kline, MorrisMathematical Thought from Ancient to Modern Times, Oxford University Press, New York, 1972.