Is there any association between referral indications for open-access upper gastrointestinal endoscopy and endoscopic findings? - van Kerkhoven, L A S; van Rijswijck, S J; van Rossum, L G M; Laheij, R J F; Witteman, E M; Tan, A C I T L; Jansen, J B M J (Endoscopy, 2007)