@article{DE_1989_25_1_a17,
     author = {S. S. Kharibegashvili},
     title = {Solvability of a characteristic problem for second-order degenerate hyperbolic systems},
     journal = {Differencialʹnye uravneni\^a},
     pages = {154--162},
     publisher = {mathdoc},
     volume = {25},
     number = {1},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1989_25_1_a17/}
}