@article{MZM_1973_13_4_a8,
     author = {G. A. Isaev},
     title = {The linear factorization of polynomial operator pencils},
     journal = {Matemati\v{c}eskie zametki},
     pages = {551--559},
     publisher = {mathdoc},
     volume = {13},
     number = {4},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1973_13_4_a8/}
}