@article{DAN_1994_335_6_a5,
     author = {A. P. Makhmudov and M. M. Rasulov},
     title = {On the perturbation of an isolated eigenvalue of finite},
     journal = {Doklady Akademii Nauk},
     pages = {694--696},
     publisher = {mathdoc},
     volume = {335},
     number = {6},
     year = {1994},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1994_335_6_a5/}
}