@article{IVM_1965_4_a12,
     author = {A. I. Perov},
     title = {Some remarks on differential inequalities},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {104--112},
     year = {1965},
     number = {4},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1965_4_a12/}
}