@article{DAN_1976_231_2_a6,
     author = {A. P. Kopylov},
     title = {Integral averages and quasi-conformal mappings},
     journal = {Doklady Akademii Nauk},
     pages = {289--291},
     publisher = {mathdoc},
     volume = {231},
     number = {2},
     year = {1976},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1976_231_2_a6/}
}