@article{DE_1987_23_10_a14,
     author = {L. M. Nevostruev},
     title = {Darboux problems for hyperbolic equations with degeneration of type and order},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1780--1786},
     publisher = {mathdoc},
     volume = {23},
     number = {10},
     year = {1987},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1987_23_10_a14/}
}