1. Generalized Inverses: Theory and Applications;Ben-Israel,1974
2. Introduction to Spectral Theory in Hilbert Space;Helmberg,1969
3. The Theory of Matrices in Numerical Analysis;Householder,1964
4. Perturbation Theory for Linear Operators;Kato,1976
5. On the reciprocal of the general algebraic matrix;Moore;Bull. Amer. Math. Soc.,1920