%0 Journal Article %A O. A. Timoshin %T The Best Approximation of a~Derivative and Analogs of Landau's Inequality in a~Half-Space %J Informatics and Automation %D 1997 %P 387-399 %V 219 %I mathdoc %U http://geodesic.mathdoc.fr/item/TRSPY_1997_219_a24/ %G ru %F TRSPY_1997_219_a24