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Not free, but don't forget Polya: http://www.amazon.com/How-Solve-Mathematical-Princeton-Science/dp/069111966X/ http://www.amazon.com/How-Solve-Mathematical-Pri
by ibejoeb 16y ago
Not free, but don't forget Polya: http://www.amazon.com/How-Solve-Mathematical-Princeton-Science/dp/069111966X/ http://www.amazon.com/How-Solve-Mathematical-Princeton-Scien...