@article{VYURM_2021_13_3_a4,
     author = {V. Sh. Roitenberg},
     title = {Bifurcations of a polycycle formed by two separatrix loops of a non-rough saddle of a dynamical system with central symmetry},
     journal = {Vestnik \^U\v{z}no-Uralʹskogo gosudarstvennogo universiteta. Seri\^a, Matematika, mehanika, fizika},
     pages = {39--46},
     publisher = {mathdoc},
     volume = {13},
     number = {3},
     year = {2021},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VYURM_2021_13_3_a4/}
}