@article{DE_1985_21_1_a25,
     author = {M. Kh. Shkhanukov},
     title = {A class of well-posed boundary value problems for second-order hyperbolic systems with nonsplittable principal sides},
     journal = {Differencialʹnye uravneni\^a},
     pages = {169--172},
     publisher = {mathdoc},
     volume = {21},
     number = {1},
     year = {1985},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1985_21_1_a25/}
}