@article{DE_1993_29_12_a8,
     author = {A. S. Berdyshev},
     title = {Nonlocal boundary value problems for an equation of mixed type in a domain with departure from a characteristic},
     journal = {Differencialʹnye uravneni\^a},
     pages = {2117--2124},
     publisher = {mathdoc},
     volume = {29},
     number = {12},
     year = {1993},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1993_29_12_a8/}
}