@article{VMUMM_1993_4_a4,
     author = {Nguyen Van Lyong},
     title = {On the eigenvalues of quadratic operator pencils},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {18--21},
     publisher = {mathdoc},
     number = {4},
     year = {1993},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_1993_4_a4/}
}