%0 Journal Article %A K. I. Babenko %A N. S. Bakhvalov %A V. M. Tikhomirov %A V. B. Demidovich %T School-Seminar “Approximation Theory and Problems of Calculus Mathematics” %J Trudy Matematicheskogo Instituta imeni V.A. Steklova %D 1987 %V 42 %N 4 %U http://geodesic.mathdoc.fr/item/RM_1987_42_4_a21/ %G ru %F RM_1987_42_4_a21