Endoscopic Resection of Submucosal Tumor of the Esophagus: Results in 62 Patients - Hyun, J H; Jeen, Y T; Chun, H J; Lee, H S; Lee, S W; Song, C W; Choi, J H; Um, S H; Kim, C D; Ryu, H S (Endoscopy, 1997)