TY  - JOUR
AU  - V. V. Arestov
TI  - Best approximation of differentiation operators
JO  - Matematičeskie zametki
PY  - 1967
SP  - 149
EP  - 154
VL  - 1
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MZM_1967_1_2_a2/
LA  - ru
ID  - MZM_1967_1_2_a2
ER  -