1. Generalized Inverses, Theory and Applications;Ben-Israel,1974
2. B.N. Datta, Numerical Linear Algebra and Applications, 1994.
3. Moore-Penrose Generalized Inverse for sums of Matrix;Fill;Ann. Math. Statist.,1997
4. http://ccrma.www.stanford/jos/lattice.
5. Theory and Applications of Numerical Analysis;Phillips,1980