Endoscopically visualized features of gastric submucosal tumors on submucosal endoscopy - Kobara, Hideki; Mori, Hirohito; Fujihara, Shintaro; Nishiyama, Noriko; Tani, Johji; Morishita, Asahiro; Oryu, Makoto; Tsutsui, Kunihiko; Masaki, Tsutomu (Endoscopy, 2014)