@article{TM_1966_92_a11,
     author = {A. P. Oskolkov},
     title = {Prior estimates of first derivatives for two-dimensional linear strongly elliptic systems and elliptic mappings},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {182--191},
     publisher = {mathdoc},
     volume = {92},
     year = {1966},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TM_1966_92_a11/}
}