@article{ZVMMF_1999_39_4_a16,
     author = {T. V. Savina},
     title = {A reflection formula for the {Helmholtz} equation with the {Neumann} condition},
     journal = {\v{Z}urnal vy\v{c}islitelʹnoj matematiki i matemati\v{c}eskoj fiziki},
     pages = {681--689},
     publisher = {mathdoc},
     volume = {39},
     number = {4},
     year = {1999},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZVMMF_1999_39_4_a16/}
}