@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},
     publisher = {mathdoc},
     volume = {36},
     year = {2010},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ETNA_2010__36__a1/}
}