@article{SM_1971_15_4_a1,
     author = {V. M. Babich},
     title = {On the asymptotics of {Green's} functions for certain wave problems. {I.~Stationary} case},
     journal = {Sbornik. Mathematics},
     pages = {513--533},
     publisher = {mathdoc},
     volume = {15},
     number = {4},
     year = {1971},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1971_15_4_a1/}
}