Threefold onset of vortex loops in superconductors with a magnetic core M. M. Doria, A. R. de C. Romaguera, M. V. Milošević and F. M. Peeters EPL, 79 4 (2007) 47006 Published online: 23 July 2007 DOI: 10.1209/0295-5075/79/47006