@article{DE_1982_18_11_a6,
     author = {G. D. Dachev},
     title = {Boundary value problems for a class of equations of mixed type},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1894--1902},
     publisher = {mathdoc},
     volume = {18},
     number = {11},
     year = {1982},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1982_18_11_a6/}
}