@article{DAN_1960_134_4_a1,
     author = {M. I. Vishik},
     title = {On the solvability of the first boundary value problem for nonlinear elliptic systems of differential equations},
     journal = {Doklady Akademii Nauk},
     pages = {749--752},
     publisher = {mathdoc},
     volume = {134},
     number = {4},
     year = {1960},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1960_134_4_a1/}
}