1. Galois actions on rings and finite Galois coverings;Auslander;Math. Scand.,1989
2. M. Auslander, I. Reiten, S. Smalø, Representation theory of Artin algebras, Cambridge Studies in Advanced Mathematics, vol. 36, Cambridge University Press, Cambridge, 1995.
3. D. Benson, Representations and cohomology I, Cambridge Studies in Advanced Mathematics, vol. 30, Cambridge University Press, Cambridge, 1991.
4. D. Benson, Representations and cohomology II, Cambridge Studies in Advanced Mathematics, vol. 31, Cambridge University Press, Cambridge, 1991.
5. Covering spaces in representation theory;Bongartz;Invent. Math.,1982