@article{DE_1990_26_4_a27,
     author = {S. L. Edelstein},
     title = {Estimates for and asymptotic behavior of solutions of a two-dimensional boundary value problem for the {Helmholtz} equation with a coefficient that depends weakly on a variable},
     journal = {Differencialʹnye uravneni\^a},
     pages = {727--729},
     publisher = {mathdoc},
     volume = {26},
     number = {4},
     year = {1990},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1990_26_4_a27/}
}