@article{IM2_1968_2_4_a11,
     author = {M. Sh. Birman},
     title = {A local criterion for the existence of wave operators},
     journal = {Izvestiya. Mathematics },
     pages = {879--906},
     publisher = {mathdoc},
     volume = {2},
     number = {4},
     year = {1968},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1968_2_4_a11/}
}