@article{DAN_1982_265_2_a3,
     author = {M. G. Gasymov and A. M. Magerramov},
     title = {Investigation of a class of differential operator pencils of even order},
     journal = {Doklady Akademii Nauk},
     pages = {277--280},
     publisher = {mathdoc},
     volume = {265},
     number = {2},
     year = {1982},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1982_265_2_a3/}
}