%0 Journal Article %A V. R. Kudashev %A S. E. Sharapov %T Inheritance of KdV symmetries under Whitham averaging and hydrodynamic symmetries of the Witham equations %J Teoretičeskaâ i matematičeskaâ fizika %D 1991 %P 40-47 %V 87 %N 1 %U http://geodesic.mathdoc.fr/item/TMF_1991_87_1_a3/ %G ru %F TMF_1991_87_1_a3