@article{DAN_1992_325_5_a6,
     author = {F. G. Maksudov and M. G. Gasanov},
     title = {On the variational theory of the spectrum of operator pencils},
     journal = {Doklady Akademii Nauk},
     pages = {915--918},
     publisher = {mathdoc},
     volume = {325},
     number = {5},
     year = {1992},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1992_325_5_a6/}
}