Nice book on integrals [duplicate]

Solution 1:

Here are some reference sources:

  1. Inside Interesting Integrals by Paul J. Nahin
  2. A Treatise on Integral Calculus Volume 1 and Volume 2 by Joseph Edwards
  3. Superhuman Integration Techniques by Andre Kessler
  4. Integration: The Feynman Way
  5. Wikipedia: Differentiation Under The Integral Sign
  6. sos440's blog

Solution 2:

Irresistible Integrals by George Boros and Victor Moll is a fantastic book for all sorts of interesting approaches to integrals.