%0 Journal Article %A A. D. Lyashko %T On the correctness of nonlinear two-level operator-difference schemes %J Doklady Akademii Nauk %D 1974 %P 263-265 %V 215 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1974_215_2_a4/ %G ru %F DAN_1974_215_2_a4