Systematics of toroidal dipole modes in Ca, Ni, Zr, and Sn isotopesA. Repko, V. O. Nesterenko, J. Kvasil and P. -G. ReinhardEur. Phys. J. A, 55 12 (2019) 242DOI: https://doi.org/10.1140/epja/i2019-12770-x