@article{SM_1974_23_1_a6,
     author = {B. R. Vainberg},
     title = {On a~point source in an inhomogeneous medium},
     journal = {Sbornik. Mathematics},
     pages = {123--148},
     year = {1974},
     volume = {23},
     number = {1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1974_23_1_a6/}
}