good problem solving books??... I'm having some difficulty solving word problems in physics and I was wondering if anyone can recommend a good problem solving book that they have read and were able to use to better their problem solving skills. I know i can build my problem solving skills through just doing practice problems but I'm trying to learn how to do them more efficiently. I just purchased "How to solve it" off of amazon, but i just wanna see if there is any other book that would be beneficial towards problem solving skills...thanks in advance!!