Radial vortex core oscillations in Bose-Einstein condensates N. Verhelst, T. Ichmoukhamedov and J. Tempere Eur. Phys. J. Special Topics, 226 12 (2017) 2829-2836 Published online: 26 July 2017 DOI: 10.1140/epjst/e2016-60374-y