TY - JOUR AU - V. Sh. Roitenberg TI - Bifurcations of a polycycle formed by two separatrix loops of a non-rough saddle of a dynamical system with central symmetry JO - Vestnik Ûžno-Uralʹskogo gosudarstvennogo universiteta. Seriâ, Matematika, mehanika, fizika PY - 2021 SP - 39 EP - 46 VL - 13 IS - 3 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/VYURM_2021_13_3_a4/ LA - ru ID - VYURM_2021_13_3_a4 ER -