@article{10_4153_CJM_2003_020_7,
     author = {Albeverio, Sergio and Makarov, Konstantin A. and Motovilov, Alexander K.},
     title = {Graph {Subspaces} and the {Spectral} {Shift} {Function}},
     journal = {Canadian journal of mathematics},
     pages = {449--503},
     year = {2003},
     volume = {55},
     number = {3},
     doi = {10.4153/CJM-2003-020-7},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CJM-2003-020-7/}
}