@article{DAN_1981_258_2_a7,
     author = {S. L. Krushkal'},
     title = {Invariant metrics and quasiconformal mappings},
     journal = {Doklady Akademii Nauk},
     pages = {293--296},
     publisher = {mathdoc},
     volume = {258},
     number = {2},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1981_258_2_a7/}
}