@article{ZNSL_1972_27_a3,
     author = {M. Sh. Birman and M. Z. Solomyak},
     title = {Remarks on spectral shift function},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {33--46},
     publisher = {mathdoc},
     volume = {27},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1972_27_a3/}
}