@article{IVM_1963_5_a15,
     author = {V. S. Serebryakova},
     title = {A bound for the domain of existence of periodic solutions},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {105--112},
     year = {1963},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1963_5_a15/}
}