@inproceedings{vladimir1990boundedness,
title={Boundedness properties of the operators of best approximation by analytic and meromorphic functions},
author={Vladimir V. Peller},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203538770811587},
booktitle={Arkiv for Matematik},
volume={30},
number={1},
pages={331-343},
year={1990},
}
Vladimir V. Peller. Boundedness properties of the operators of best approximation by analytic and meromorphic functions. 1990. Vol. 30. In Arkiv for Matematik. pp.331-343. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203538770811587.