@article{DAN_1981_258_6_a4,
     author = {V. A. Lebedev},
     title = {Some spectral properties of {Sobolev} elliptic problems},
     journal = {Doklady Akademii Nauk},
     pages = {1304--1308},
     publisher = {mathdoc},
     volume = {258},
     number = {6},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1981_258_6_a4/}
}