@article{Romanyuk_Romanyuk_Pozharska_Hembarska_2023CarpMathPubl, 
title={Characteristics of linear and nonlinear approximation of isotropic classes of periodic multivariate functions}, 
author={Romanyuk, A.S. and Romanyuk, V.S. and Pozharska, K. and Hembarska, S.B.}, 
journal={Carpathian Mathematical Publications}, 
number={1}, 
year={2023}, 
pages={78–94},
volume={15}, 
DOI={10.15330/cmp.15.1.78-94}, 
 }