@article{SM_1984_49_1_a4,
     author = {D. G. Vasil'ev},
     title = {Asymptotic behavior of the spectrum of pseudodifferential operators with small parameters},
     journal = {Sbornik. Mathematics},
     pages = {61--72},
     year = {1984},
     volume = {49},
     number = {1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1984_49_1_a4/}
}