TY  - JOUR
AU  - N. A. Il'yasov
TI  - An inverse theorem of approximation theory of periodic functions in various metrics
JO  - Matematičeskie zametki
PY  - 1992
SP  - 53
EP  - 61
VL  - 52
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MZM_1992_52_2_a5/
LA  - ru
ID  - MZM_1992_52_2_a5
ER  -