@article{ZNSL_1995_229_a3,
     author = {L. Yu. Kolotilina},
     title = {Twofold deflation preconditioning of linear algebraic {systems.~I.~Theory}},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {95--152},
     publisher = {mathdoc},
     volume = {229},
     year = {1995},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1995_229_a3/}
}