@article{DE_1991_27_3_a19,
     author = {A. I. Vahabov},
     title = {Conditions for the well-posedness of two-dimensional mixed problems for hyperbolic systems},
     journal = {Differencialʹnye uravneni\^a},
     pages = {531--533},
     publisher = {mathdoc},
     volume = {27},
     number = {3},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1991_27_3_a19/}
}