@article{DE_1983_19_4_a9,
     author = {E. S. Gubanova},
     title = {Some questions of the theory of second-order elliptic equations on the plane},
     journal = {Differencialʹnye uravneni\^a},
     pages = {618--621},
     publisher = {mathdoc},
     volume = {19},
     number = {4},
     year = {1983},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1983_19_4_a9/}
}