\Bibitem{1} \paper Jamalbek Tussupov (to the 60th birthday) \jour Eurasian Math. J. \yr 2017 \vol 8 \issue 3 \pages 9 \mathnet{http://mi.mathnet.ru/emj261} \isi{https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=Publons&SrcAuth=Publons_CEL&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=000416973500002}