\Bibitem{Vak95} \by S.~B.~Vakarchuk \paper Best linear methods of approximation and widths of classes of analytic functions in a disk \jour Mat. Zametki \yr 1995 \vol 57 \issue 1 \pages 30--39 \mathnet{http://mi.mathnet.ru/mzm1919} \mathscinet{http://mathscinet.ams.org/mathscinet-getitem?mr=1339210} \zmath{https://zbmath.org/?q=an:0862.41018} \transl \jour Math. Notes \yr 1995 \vol 57 \issue 1 \pages 21--27 \crossref{https://doi.org/10.1007/BF02309390} \isi{https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=Publons&SrcAuth=Publons_CEL&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=A1995TA13700003}