Follow-up near-infrared spectroscopy of ultraluminous infrared galaxies observed by ISO H. Dannerbauer, D. Rigopoulou, D. Lutz, R. Genzel, E. Sturm and A. F. M. Moorwood A&A, 441 3 (2005) 999-1010 Published online: 23 September 2005 DOI: 10.1051/0004-6361:20052812