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@article{DE_1982_18_6_a9, author = {M. P. Grigolia}, title = {A modified characteristic problem for hyperbolic systems with singularities}, journal = {Differencialʹnye uravneni\^a}, pages = {1005--1014}, publisher = {mathdoc}, volume = {18}, number = {6}, year = {1982}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1982_18_6_a9/} }
M. P. Grigolia. A modified characteristic problem for hyperbolic systems with singularities. Differencialʹnye uravneniâ, Tome 18 (1982) no. 6, pp. 1005-1014. http://geodesic.mathdoc.fr/item/DE_1982_18_6_a9/