@article{IVM_1959_1_a4,
     author = {I. M. Volk},
     title = {On the limit cycle of a~dynamical system of differential equations in a~class of cases},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {35--44},
     publisher = {mathdoc},
     number = {1},
     year = {1959},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1959_1_a4/}
}