@article{DE_1985_21_1_a19,
     author = {S. S. Kharibegashvili},
     title = {A boundary value problem for second-order normally hyperbolic systems with variable coefficients},
     journal = {Differencialʹnye uravneni\^a},
     pages = {149--155},
     publisher = {mathdoc},
     volume = {21},
     number = {1},
     year = {1985},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1985_21_1_a19/}
}