@article{DE_1981_17_1_a10,
     author = {S. K. Kumykova},
     title = {A problem with nonlocal conditions on characteristics for a hyperbolic equation that degenerates inside the domain},
     journal = {Differencialʹnye uravneni\^a},
     pages = {81--90},
     publisher = {mathdoc},
     volume = {17},
     number = {1},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1981_17_1_a10/}
}