Erratum to: Mathematical analysis of whispering gallery modes in graded index optical micro-disk resonators - Eur. Phys. J. D (2020) 74: 221, https://doi.org/10.1140/epjd/e2020-10303-5
Eur. Phys. J. D, 74 12 (2020) 242
Published online: 08 December 2020
DOI: 10.1140/epjd/e2020-10605-6