TY  - JOUR
AU  - E. A. Sevast'yanov
TI  - The degree of rational approximation of functions and their differentiability
JO  - Izvestiya. Mathematics 
PY  - 1981
SP  - 595
EP  - 600
VL  - 17
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/IM2_1981_17_3_a6/
LA  - en
ID  - IM2_1981_17_3_a6
ER  -