@article{DAN_1987_297_5_a1,
     author = {A. N. Vagin},
     title = {Distortion theory for multivalent quasiconformal mappings of the},
     journal = {Doklady Akademii Nauk},
     pages = {1036--1039},
     publisher = {mathdoc},
     volume = {297},
     number = {5},
     year = {1987},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1987_297_5_a1/}
}