1. Noncommutative Rings;Herstein,1968
2. Structure of Rings;Jacobson,1964
3. T.J. Laffey and E. Meehan, Factorization of polynomials using commuting matrices, to appear.
4. T.J. Laffey and E. Meehan, Factorization of polynomials using unipotent Jordan blocks Appl. Math. Lett., to appear.