@article{DAN_1983_272_6_a8,
     author = {S. Z. Levendorskii},
     title = {Spectral asymptotics of nonlinear pencils and operators with nonempty essential spectrum},
     journal = {Doklady Akademii Nauk},
     pages = {1314--1317},
     publisher = {mathdoc},
     volume = {272},
     number = {6},
     year = {1983},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1983_272_6_a8/}
}