%0 Journal Article %A S. P. Novikov %T The geometry of conservative systems of hydrodynamic type. The method of averaging for field-theoretical systems %J Trudy Matematicheskogo Instituta imeni V.A. Steklova %D 1985 %P 85-98 %V 40 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/RM_1985_40_4_a10/ %G en %F RM_1985_40_4_a10