Near infra-red spectroscopy of the asteroid 21 Lutetia - I. New results of long-term campaign M. Birlan, P. Vernazza, M. Fulchignoni, M. A. Barucci, P. Descamps, R. P. Binzel and S. J. Bus A&A, 454 2 (2006) 677-681 Published online: 11 July 2006 DOI: 10.1051/0004-6361:20054460