TY  - JOUR
AU  - V. A. Klyachin
TI  - Approximation of the gradient of a function on the basis of a special
JO  - Izvestiya. Mathematics
PY  - 2018
SP  - 1136
EP  - 1147
VL  - 82
IS  - 6
UR  - http://geodesic.mathdoc.fr/item/IM2_2018_82_6_a2/
LA  - en
ID  - IM2_2018_82_6_a2
ER  -