@article{MZM_1989_45_6_a13,
     author = {V. N. Pyvovarchyk},
     title = {The spectrum of quadratic operator pencils in the right half-plane},
     journal = {Matemati\v{c}eskie zametki},
     pages = {101--103},
     publisher = {mathdoc},
     volume = {45},
     number = {6},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1989_45_6_a13/}
}