\Bibitem{Shi82} \by E.~V.~Shikin \paper Equations of isometric imbeddings in three-dimensional Euclidean space of two-dimensional manifolds of negative curvature \jour Mat. Zametki \yr 1982 \vol 31 \issue 4 \pages 601--612 \mathnet{http://mi.mathnet.ru/mzm6103} \mathscinet{http://mathscinet.ams.org/mathscinet-getitem?mr=657721} \zmath{https://zbmath.org/?q=an:0499.53004|0491.53002} \transl \jour Math. Notes \yr 1982 \vol 31 \issue 4 \pages 305--312 \crossref{https://doi.org/10.1007/BF01138942} \isi{https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=Publons&SrcAuth=Publons_CEL&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=A1982PP32900026}