%0 Journal Article %A Yu. V. Egorov %T Hyperbolic equations with discontinuous coefficients %J Doklady Akademii Nauk %D 1960 %P 514-517 %V 134 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1960_134_3_a3/ %G ru %F DAN_1960_134_3_a3