Mode spectra of magnetic and dielectric plasmon spheres obtained from Mie scattering and free oscillation theoriesJerzy Krupka, Bartlomiej Salski, Adam Pacewicz and Pawel KopytEur. Phys. J. B, 95 1 (2022) 1DOI: https://doi.org/10.1140/epjb/s10051-021-00257-x