@article{RM_1961_16_5_a14,
     author = {V. F. Tkachev},
     title = {Generalization of a~theorem of {H.~Poincar\'e} on the non-existence of limit cycles and some other results},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     publisher = {mathdoc},
     volume = {16},
     number = {5},
     year = {1961},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/RM_1961_16_5_a14/}
}