%0 Journal Article %A S. N. Kruzhkov %T Periodic solutions of nonlinear second order parabolic equations %J Differencialʹnye uravneniâ %D 1970 %P 731-740 %V 6 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1970_6_4_a15/ %G ru %F DE_1970_6_4_a15