Methods of graded rings The Category of Graded Rings. The Category of Graded Modules. Modules over Stronly Graded Rings. Graded Clifford Theory. Internal Homogenization. External Homogenization. Smash Products. Localization of Graded Rings. Application to Gradability. Appendix A:Some Category Theory. Appendix B: Dimensions in an abelian Category. Bibliography. Index.