@article{VMUMM_1988_1_a26,
     author = {A. M. Lopatnikov},
     title = {Asymptotic behavior of the spectral function for a class of hypoelliptic operators},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {92--94},
     year = {1988},
     number = {1},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_1988_1_a26/}
}