TY  - JOUR
AU  - S. B. Vakarchuk
AU  - A. V. Shvachko
TI  - Inequalities of Kolmogorov's type for derived functions in two variables and application to approximation by an ``angle''
JO  - Izvestiâ vysših učebnyh zavedenij. Matematika
PY  - 2015
SP  - 3
EP  - 22
IS  - 11
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/IVM_2015_11_a0/
LA  - ru
ID  - IVM_2015_11_a0
ER  -