%0 Journal Article %A G. V. Sandrakov %T Averaging principles for eguations with rapidly oscillatory coefficients %J Sbornik. Mathematics %D 1991 %P 503-553 %V 68 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/SM_1991_68_2_a9/ %G en %F SM_1991_68_2_a9