@article{DAN_1984_279_2_a10,
     author = {A. Toraev},
     title = {Oscillation of elliptic operators and the structure of their},
     journal = {Doklady Akademii Nauk},
     pages = {306--309},
     publisher = {mathdoc},
     volume = {279},
     number = {2},
     year = {1984},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1984_279_2_a10/}
}