@article{GDZPPN001182803,
title = {Preconditioning Indefinite Discretization Matrices.},
journal = {Numerische Mathematik},
volume = {56},
year = {1989},
pages = {719-734},
zbl = {0663.65042},
url = {http://dml.mathdoc.fr/item/GDZPPN001182803}
}
Yserentant, Harry. Preconditioning Indefinite Discretization Matrices.. Numerische Mathematik, Tome 56 (1989) pp. 719-734. http://gdmltest.u-ga.fr/item/GDZPPN001182803/