Voir la notice de l'article provenant de la source Math-Net.Ru
@article{DAN_1973_209_4_a10, author = {V. M. Petkov}, title = {On the {Cauchy} problem for first-order hyperbolic systems with multiple characteristics}, journal = {Doklady Akademii Nauk}, pages = {795--797}, publisher = {mathdoc}, volume = {209}, number = {4}, year = {1973}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1973_209_4_a10/} }
V. M. Petkov. On the Cauchy problem for first-order hyperbolic systems with multiple characteristics. Doklady Akademii Nauk, Tome 209 (1973) no. 4, pp. 795-797. http://geodesic.mathdoc.fr/item/DAN_1973_209_4_a10/