@article{DE_1988_24_10_a11,
     author = {M. P. Grigolia},
     title = {On the uniqueness of the solution of the characteristic problem for higher-order hyperbolic differential equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1747--1756},
     publisher = {mathdoc},
     volume = {24},
     number = {10},
     year = {1988},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1988_24_10_a11/}
}