%0 Journal Article %A M. I. Vishik %A A. V. Fursikov %T Some questions in the theory of nonlinear elliptic and parabolic equations %J Sbornik. Mathematics %D 1974 %P 287-318 %V 23 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/SM_1974_23_2_a7/ %G en %F SM_1974_23_2_a7