1. The orbit space of the action of gauge transformation group on connections;Abbati;J. Geom. Phys.,1989
2. The Lie group of automorphisms of a principal bundle;Abbati;J. Geom. Phys.,1989
3. General Topology;Bourbaki,1989
4. Lie Groups and Lie Algebras;Bourbaki,1989
5. Introduction to Compact Transformation Groups;Bredon,1972