@article{IVM_1966_5_a12,
     author = {R. M. Nasyrov},
     title = {Qualitative study of a~singular case of stability in the case of two zero-roots},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {100--111},
     year = {1966},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1966_5_a12/}
}