TY  - JOUR
AU  - I. I. Ibragimov
TI  - Extremum problems in the class of trigonometric polynomials
JO  - Doklady Akademii Nauk
PY  - 1958
SP  - 415
EP  - 417
VL  - 121
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DAN_1958_121_3_a4/
LA  - ru
ID  - DAN_1958_121_3_a4
ER  -