The effect of sedation on the quality of upper gastrointestinal endoscopy: an investigator-blinded, randomized study comparing propofol with midazolam - Meining, A; Semmler, V; Kassem, A M; Sander, R; Frankenberger, U; Burzin, M; Reichenberger, J; Bajbouj, M; Prinz, C; Schmid, R M (Endoscopy, 2007)