@article{DAN_1989_308_1_a4,
     author = {Yu. V. Zasorin},
     title = {The {Helmholtz} equation with an anisotropic source},
     journal = {Doklady Akademii Nauk},
     pages = {27--31},
     publisher = {mathdoc},
     volume = {308},
     number = {1},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1989_308_1_a4/}
}