\Bibitem{IvrFed86} \by V.~Ya.~Ivrii, S.~I.~Fedorova \paper Dilatation and the asymptotics of the eigenvalues of spectral problems with singularities \jour Funktsional. Anal. i Prilozhen. \yr 1986 \vol 20 \issue 4 \pages 29--34 \mathnet{http://mi.mathnet.ru/faa1312} \mathscinet{http://mathscinet.ams.org/mathscinet-getitem?mr=878042} \zmath{https://zbmath.org/?q=an:0628.35077} \transl \jour Funct. Anal. Appl. \yr 1986 \vol 20 \issue 4 \pages 277--281 \crossref{https://doi.org/10.1007/BF01083493} \isi{https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=Publons&SrcAuth=Publons_CEL&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=A1986J362600004}