%0 Journal Article
%A V. A. Klyachin
%T Modified Delaunay empty sphere condition in the problem of approximation of the gradient
%J Izvestiya. Mathematics 
%D 2016
%P 549-556
%V 80
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/IM2_2016_80_3_a5/
%G en
%F IM2_2016_80_3_a5