@article{DAN_1991_319_3_a21,
     author = {Yu. D. Pletner},
     title = {Asymptotics of the fundamental solution of the equation of},
     journal = {Doklady Akademii Nauk},
     pages = {604--607},
     publisher = {mathdoc},
     volume = {319},
     number = {3},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1991_319_3_a21/}
}