@article{DAN_1975_224_3_a4,
     author = {A. I. Ibragimov},
     title = {On the behavior on the boundary of solutions of a degenerate second-order elliptic equation},
     journal = {Doklady Akademii Nauk},
     pages = {519--522},
     publisher = {mathdoc},
     volume = {224},
     number = {3},
     year = {1975},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1975_224_3_a4/}
}