Meissner effect and vortex dynamics in quark stars - A model for soft gamma-ray repeaters R. Ouyed, Ø. Elgarøy, H. Dahle and P. Keränen A&A, 420 3 (2004) 1025-1032 Published online: 04 June 2004 DOI: 10.1051/0004-6361:20034180