@article{DAN_1988_298_5_a7,
     author = {N. G. Marchuk},
     title = {Symmetric hyperbolic systems of second-order equations},
     journal = {Doklady Akademii Nauk},
     pages = {1063--1068},
     publisher = {mathdoc},
     volume = {298},
     number = {5},
     year = {1988},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1988_298_5_a7/}
}