%0 Journal Article %A A. D. Myshkis %A N. P. Parshikova %T Estimation of the value of a known functional from an unknown solution %J Differencialʹnye uravneniâ %D 1973 %P 754-756 %V 9 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1973_9_4_a22/ %G ru %F DE_1973_9_4_a22