@article{VMUMM_1986_1_a15,
     author = {A. V. Efremov and D. V. Efremov},
     title = {Asymptotic behavior of the spectrum of an elliptic operator invariant relative to a discrete group of diffeomorphisms},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {57--59},
     publisher = {mathdoc},
     number = {1},
     year = {1986},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_1986_1_a15/}
}