@article{MABA_1994_8_2-3_a4,
     author = {P. S. Vassilevski and S. I. Petrova and R. D. Lazarov},
     title = {Preconditioning {Elliptic} {Problems} on {Grids} with {Multilevel} {Local} {Refinement}},
     journal = {Mathematica balkanica},
     pages = {179},
     publisher = {mathdoc},
     volume = {8},
     number = {2-3},
     year = {1994},
     url = {http://geodesic.mathdoc.fr/item/MABA_1994_8_2-3_a4/}
}