The study of oscillations of regular mechanical systems with broken cyclic symmetry as one of the hallmarks of the G.S. Pisarenko Institute for Problems of Strength of the NAS of Ukraine (in memory of Corresponding Member of the NAS of Ukraine A.P. Zinkov - V. T. Troshchenko; V. V. Matvieiev; K. V. Savchenko (Visnyk of the National Academy of Sciences of Ukraine, 2022)