Endoscopic, histologic, and electron microscopic description of novel small vesicles with gastric heterotopia, intestinal metaplasia, and/or submucosal glands at the gastroesophageal junction - Mönkemüller, Klaus; Martínez-Alcalá, Álvaro; Unnewehr-Linares, Claudia; Fry, Lucía C. (Endoscopy, 2022)