Shock acceleration as origin of the radio relic in A 521? S. Giacintucci, T. Venturi, G. Macario, D. Dallacasa, G. Brunetti, M. Markevitch, R. Cassano, S. Bardelli and R. Athreya A&A, 486 2 (2008) 347-358 Published online: 16 April 2008 DOI: 10.1051/0004-6361:200809459