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@article{IVM_1973_6_a14, author = {L. D. \`Eskin}, title = {The spectrum of singular differential operators}, journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika}, pages = {103--116}, publisher = {mathdoc}, number = {6}, year = {1973}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/IVM_1973_6_a14/} }
L. D. Èskin. The spectrum of singular differential operators. Izvestiâ vysših učebnyh zavedenij. Matematika, no. 6 (1973), pp. 103-116. http://geodesic.mathdoc.fr/item/IVM_1973_6_a14/