Magnetars as persistent hard X-ray sources: INTEGRAL discovery of a hard tail in SGR 1900+14 D. Götz, S. Mereghetti, A. Tiengo and P. Esposito A&A, 449 2 (2006) L31-L34 Published online: 21 March 2006 DOI: 10.1051/0004-6361:20064870