I was trying to solve some integrals that appear in quantum electrodynamics but I was not able to do it on my own.
$$1/6\int_0^1 \int_0^1 { u^3 z^2(1-z^2/3) \over [u^2(1-z^2)+4(1-u)]}dudz $$
I know the answer should be $$(\pi^2 / 18) - (115 / 216)$$
Can anyone help me solve this or at least point me to a book that might cover those double integrals? I would realy appreciate it. In attachment you have an image of the paper this came from. Of course I have problems with the other integrals too. But I chose to start with this one.
Thank you.
