Upper limits on CO 4.7 μm emission from disks around five Herbig Ae/Be stars A. Carmona, M. E. van den Ancker, W.-F. Thi, M. Goto and Th. Henning A&A, 436 3 (2005) 977-982 Published online: 03 June 2005 DOI: 10.1051/0004-6361:20052764