http://en.wikipedia.org/wiki/Differentiation_under_the_integral_sign#Popular_culture http://en.wikipedia.org/wiki/Differentiation_under_the_integ... I don't kn

http://en.wikipedia.org/wiki/Differentiation_under_the_integral_sign#Popular_culture http://en.wikipedia.org/wiki/Differentiation_under_the_integ... I don't know about recommending the practical-man book; I don't recall him mentioning it elsewhere. He quoted "What one fool can do, another can" (from Calculus Made Easy) I think more than once. I've skimmed Calculus Made Easy and it seems nice, and short.