1. Methods for sparse linear least squares problems;Björck,1976
2. Comment on the iterative refinement of least squares solutions;Björck;J. Amer. Stat. Assoc.,1978
3. Numerical algorithms for linear least squares problems;Björck,1978
4. A preconditioned conjugate gradient method for solving a class of non-symmetric linear systems;Dongarra,1981
5. Performance evaluation of codes for sparse matrices;Duff,1978