@article{ETNA_2010__36__a1,
     author = {Axelsson,  Owe and Kar\'atson,  J\'anos},
     title = {Condition number analysis for various forms of block matrix preconditioners},
     journal = {Electronic transactions on numerical analysis},
     year = {2010},
     volume = {36},
     zbl = {1205.65145},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ETNA_2010__36__a1/}
}