@article{10_21136_AM_2017_0222_17,
     author = {Axelsson, Owe},
     title = {Preconditioning of two-by-two block matrix systems with square matrix blocks, with applications},
     journal = {Applications of Mathematics},
     pages = {537--559},
     publisher = {mathdoc},
     volume = {62},
     number = {6},
     year = {2017},
     doi = {10.21136/AM.2017.0222-17},
     mrnumber = {3745740},
     zbl = {06861545},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/AM.2017.0222-17/}
}