Low Frequency of Colorectal Dysplasia in Patients with Long-Standing Inflammatory Bowel Disease Colitis: Detection by Fluorescence Endoscopy - Ochsenkühn, T; Tillack, C; Stepp, H; Diebold, J; Ott, S J; Baumgartner, R; Brand, S; Göke, B; Sackmann, M (Endoscopy, 2006)