@article{DAN_1991_316_5_a4,
     author = {V. V. Katrakhov},
     title = {Singular boundary value problems for some elliptic equations in},
     journal = {Doklady Akademii Nauk},
     pages = {1047--1050},
     year = {1991},
     volume = {316},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1991_316_5_a4/}
}