# Finding sums of infinite convergent series

All calculus textbooks I know of seem to be obsessed with the question of which infinite series is convergent and which is not but none address the question of how to find the sum of an infinite convergent series . What books contain systematic treatment of methods of finding sums of series ?

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Finding the sum of a convergent series is generally a next-to-impossible task. Consider the (apparently relatively simple) case of $\sum_{n=1}^\infty n^{-r}$ for $r>1$. –  Andrea Mori Dec 19 '12 at 10:58
A good deal of Graham, Knuth, & Patashni, Concrete Mathematics, is devoted to methods for solving this very difficult problem in certain cases. –  Brian M. Scott Dec 19 '12 at 11:10