@article{DE_1979_15_1_a10,
     author = {S. K. Kumykova},
     title = {A boundary value problem for a degenerate hyperbolic equation in a characteristic crescent},
     journal = {Differencialʹnye uravneni\^a},
     pages = {79--91},
     publisher = {mathdoc},
     volume = {15},
     number = {1},
     year = {1979},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1979_15_1_a10/}
}