@article{AA_2008_20_4_a6,
     author = {V. E. Fedorov and O. A. Ruzakova},
     title = {On solvability of perturbed {Sobolev} type equations},
     journal = {Algebra i analiz},
     pages = {189--217},
     publisher = {mathdoc},
     volume = {20},
     number = {4},
     year = {2008},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AA_2008_20_4_a6/}
}