@article{JRAM_1997__491_153945,
     author = {Gerald Teschl},
     title = {Spectral deformations of {Jacobi} operators.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {1--16},
     publisher = {mathdoc},
     volume = {491},
     year = {1997},
     zbl = {0886.39005},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1997__491_153945/}
}