Influence of UV radiation from a massive YSO on the chemistry of its envelope P. Stäuber, S. D. Doty, E. F. van Dishoeck, J. K. Jørgensen and A. O. Benz A&A, 425 2 (2004) 577-589 Published online: 21 September 2004 DOI: 10.1051/0004-6361:20048091