TY  - JOUR
AU  - V. A. Klyachin
TI  - Modified Delaunay empty sphere condition in the problem of approximation of the gradient
JO  - Izvestiya. Mathematics 
PY  - 2016
SP  - 549
EP  - 556
VL  - 80
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/IM2_2016_80_3_a5/
LA  - en
ID  - IM2_2016_80_3_a5
ER  -