Voir la notice de l'article provenant de la source Math-Net.Ru
@article{MZM_1991_49_3_a21, author = {M. I. Gil'}, title = {Perturbation of the spectra of operators of a certain class}, journal = {Matemati\v{c}eskie zametki}, pages = {149--151}, publisher = {mathdoc}, volume = {49}, number = {3}, year = {1991}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/MZM_1991_49_3_a21/} }
M. I. Gil'. Perturbation of the spectra of operators of a certain class. Matematičeskie zametki, Tome 49 (1991) no. 3, pp. 149-151. http://geodesic.mathdoc.fr/item/MZM_1991_49_3_a21/