The distribution of maser stars in the inner Milky Way: the effect of a weak, rotating bar H. J. Habing, M. N. Sevenster, M. Messineo, G. van de Ven and K. Kuijken A&A, 458 1 (2006) 151-162 Published online: 16 October 2006 DOI: 10.1051/0004-6361:20054480