@article{ETNA_2006__22__a3,
     author = {Greif, Chen and Sch\"otzau, Dominik},
     title = {Preconditioners for saddle point linear systems with highly singular $(1,1)$ blocks},
     journal = {Electronic transactions on numerical analysis},
     pages = {114--121},
     publisher = {mathdoc},
     volume = {22},
     year = {2006},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ETNA_2006__22__a3/}
}