An analysis of HST UV spectra of Cyg OB2 stars A. Herrero, J. Puls, L. J. Corral, R. P. Kudritzki and M. R. Villamariz A&A, 366 2 (2001) 623-635 Published online: 15 February 2001 DOI: 10.1051/0004-6361:20000236