A Note on Preconditioning Nonsymmetric Matrices
Ilse C. F. Ipsen · SIAM Journal on Scientific Computing · 2001
The preconditioners for indefinite matrices of KKT form in [M. F. Murphy, G. H. Golub, and A. J. Wathen, SIAM J. Sci. Comput., 21 (2000), pp. 1969--1972] are extended to general nonsymmetric matrices.