@article{UZKU_2012_154_3_a14,
     author = {V. S. Mokeichev and A. M. Sidorov},
     title = {Matrix {Eigenvalues} in {Analytic} {Perturbation} {Theory} for {Linear} {Operators}},
     journal = {U\v{c}\"enye zapiski Kazanskogo universiteta. Seri\^a Fiziko-matemati\v{c}eskie nauki},
     pages = {158--172},
     publisher = {mathdoc},
     volume = {154},
     number = {3},
     year = {2012},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/UZKU_2012_154_3_a14/}
}