@article{AA_1992_4_6_a0,
     author = {M. Sh. Birman and D. R. Yafaev},
     title = {Spectral properties of the scattering matrix},
     journal = {Algebra i analiz},
     pages = {1--27},
     year = {1992},
     volume = {4},
     number = {6},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AA_1992_4_6_a0/}
}