I don't have my copies here to check, but I thiiiiiiiiink Weinberg, The Quantum Theory of Fields, vol. 3 and Wess and Bagger, Supersymmetry and Supergravity both discuss it. I'll give you a more concrete answer when I'm on campus.
The original proof is not very solid, and harder to follow. Weinberg vol 3 does a good job with both theorems.
Or try this http://arxiv.org/abs/hep-th/9605147