@article{RM_1976_31_4_a25,
     author = {V. L. Roitburd},
     title = {The quasiclassical asymptotic behavior of the spectrum of a pseudo-differential operator},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     year = {1976},
     volume = {31},
     number = {4},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/RM_1976_31_4_a25/}
}