%0 Journal Article %A V. V. Shan'kov %T Difference operators with variable step %J Informatics and Automation %D 1987 %P 229-230 %V 180 %I mathdoc %U http://geodesic.mathdoc.fr/item/TRSPY_1987_180_a141/ %G ru %F TRSPY_1987_180_a141