@article{KUIPM_1992_a12,
     author = {A. M. Sidorov},
     title = {The basis property of analytically perturbed eigenelements},
     journal = {Issledovaniya po Prikladnoi Matematike i Informatike},
     pages = {115--121},
     publisher = {mathdoc},
     year = {1992},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/KUIPM_1992_a12/}
}