Detection of additional Wolf-Rayet stars in the starburst cluster Westerlund 1 with SOAR J. H. Groh, A. Damineli, M. Teodoro and C. L. Barbosa A&A, 457 2 (2006) 591-594 Published online: 12 September 2006 DOI: 10.1051/0004-6361:20064929