@article{DE_1968_4_12_a9,
     author = {N. J. Yurchuk},
     title = {A partly characteristic boundary value problem for a certain form of partial differential {equations.~I}},
     journal = {Differencialʹnye uravneni\^a},
     pages = {2258--2267},
     year = {1968},
     volume = {4},
     number = {12},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1968_4_12_a9/}
}