@article{TRSPY_1968_103_a4,
     author = {I. A. Danilova},
     title = {Exterior boundary value problems for the {Helmholtz} equation},
     journal = {Informatics and Automation},
     pages = {58--72},
     publisher = {mathdoc},
     volume = {103},
     year = {1968},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TRSPY_1968_103_a4/}
}