\Bibitem{Slo15} \by V.~A.~Sloushch \paper Discrete spectrum of the periodic Schr\"odinger operator with a~variable metric perturbed by a~nonnegative rapidly decaying potential \jour Algebra i Analiz \yr 2015 \vol 27 \issue 2 \pages 196--210 \mathnet{http://mi.mathnet.ru/aa1429} \mathscinet{http://mathscinet.ams.org/mathscinet-getitem?mr=3444465} \elib{https://elibrary.ru/item.asp?id=24849881} \transl \jour St. Petersburg Math. J. \yr 2016 \vol 27 \issue 2 \pages 317--326 \crossref{https://doi.org/10.1090/spmj/1388} \isi{https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=Publons&SrcAuth=Publons_CEL&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=000374002600007} \scopus{https://www.scopus.com/record/display.url?origin=inward&eid=2-s2.0-84958253482}