Coherence loss in phase-referenced VLBI observations (Corrigendum) I. Martí-Vidal, E. Ros, M. A. Pérez-Torres, J. C. Guirado, S. Jiménez-Monferrer and J. M. Marcaide A&A, 533 (2011) C1 Published online: 07 September 2011 DOI: 10.1051/0004-6361/201014203e