Media type: E-Article Title: Ling classification applied in the preoperative safety and effectiveness assessment of POEM Contributor: Chai, Ningli; Zhang, Xiaobin; Xiong, Ying; Ding, Hui; Feng, Jia; Li, Yingying; Yao, Shuangzhe; Niu, Xiaotong; Linghu, Enqiang imprint: Springer Science and Business Media LLC, 2017 Published in: Surgical Endoscopy Language: English DOI: 10.1007/s00464-016-4981-z ISSN: 0930-2794; 1432-2218 Keywords: Surgery Origination: Footnote: