On the normal subgroups of GL(2,A)
For a commutative local ring A, the authors determine the normal subgroups of the general linear group GL(2,A). Since every Artinian commutative ring A is a finite direct sum of local rings they are also able to derive a description for all normal subgroups of GL(2,A) for an Artinian ring A.
scientific article; zbMATH DE number 4198328