@article{FAA_1989_23_1_a15,
     author = {E. D. Nursultanov},
     title = {Certain properties of the roots of a weakly hyperbolic operator pencil},
     journal = {Funkcionalʹnyj analiz i ego prilo\v{z}eni\^a},
     pages = {78--79},
     publisher = {mathdoc},
     volume = {23},
     number = {1},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/FAA_1989_23_1_a15/}
}