@article{MZM_1980_28_5_a4,
     author = {V. M. Babich},
     title = {Hadamard's method and the asymptotics of the spectral function of a second-order differential operator},
     journal = {Matemati\v{c}eskie zametki},
     pages = {689--694},
     publisher = {mathdoc},
     volume = {28},
     number = {5},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1980_28_5_a4/}
}