[O I] 6300 Å emission in Herbig Ae/Be systems: Signature of Keplerian rotation B. Acke, M. E. van den Ancker and C. P. Dullemond A&A, 436 1 (2005) 209-230 Published online: 20 May 2005 DOI: 10.1051/0004-6361:20042484