I am looking for a nice and rigorous proof of Frucht's theorem (every (finite) group is isomorphic to a automorphism group of a (finite) graph). So far, i have looked at the following:
Combinatorial Problems and Exercises by Laszlo Lovasz
Theory of graphs by Oystein Ore
Frucht's original proof (in german)
I was just wondering if someones knows of a nice(r) proof somewhere. I am not quite satisfied with the ones I looked at, I wish some things would be explained more elaborately and rigorously. Both english and german sources would be okay. Thanks in advance!