Kolesnikov, E.K. and Klushnikov, G.N. 2020. The allowed regions in the problem concerning dynamics of a charged particle in a superposition of dipole and uniform magnetic fields. Vestnik of Saint Petersburg University. Mathematics. Mechanics. Astronomy. 3, 2 (Oct. 2020), 1. DOI:https://doi.org/10.21638/11701/spbu01.2016.213.