%0 Journal Article %A V. M. Teshukov %T On the hyperbolicity of long wave equations %J Doklady Akademii Nauk %D 1985 %P 555-559 %V 284 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1985_284_3_a9/ %G ru %F DAN_1985_284_3_a9