A Randomized Prospective Trial Comparing Unsedated Esophagoscopy via Transnasal and Transoral Routes Using a 4-mm Video Endoscope with Conventional Endoscopy with Sedation - Thota, P N; Zuccaro Jr , G; Vargo II, J J; Conwell, D L; Dumot, J A; Xu, M (Endoscopy, 2005)