Voir la notice de l'article provenant de la source Math-Net.Ru
@article{MZM_1992_51_4_a13, author = {M. A. Pankratov}, title = {Evolution of the complex spectrum of a periodic operator}, journal = {Matemati\v{c}eskie zametki}, pages = {101--108}, publisher = {mathdoc}, volume = {51}, number = {4}, year = {1992}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/MZM_1992_51_4_a13/} }
M. A. Pankratov. Evolution of the complex spectrum of a periodic operator. Matematičeskie zametki, Tome 51 (1992) no. 4, pp. 101-108. http://geodesic.mathdoc.fr/item/MZM_1992_51_4_a13/