Rotation curves and metallicity gradients from HII regions in spiral galaxies I. Márquez, J. Masegosa, M. Moles, J. Varela, D. Bettoni and G. Galletta A&A, 393 2 (2002) 389-407 Published online: 23 September 2002 DOI: 10.1051/0004-6361:20021036