@article{ETNA_2000__10__a0,
     author = {Zhang,  Jun},
     title = {On preconditioning {Schur} complement and {Schur} complement preconditioning},
     journal = {Electronic transactions on numerical analysis},
     pages = {115--130},
     year = {2000},
     volume = {10},
     zbl = {0951.65042},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ETNA_2000__10__a0/}
}