TY  - JOUR
AU  - S. B. Vakarchuk
TI  - Best Polynomial Approximations and Widths of Classes of Functions in the Space~$L_2$
JO  - Matematičeskie zametki
PY  - 2018
SP  - 307
EP  - 311
VL  - 103
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MZM_2018_103_2_a12/
LA  - ru
ID  - MZM_2018_103_2_a12
ER  -