求助格式： 【作者】Bing Li 1, Qiang Shi 1, En-Pan Xu 【文章标题】Prediction of technically difficult endoscopic submucosal dissection for large superficial colorectal tumors: a novel clinical score model 【期刊名，年份，卷（期），起止页】Gastrointest Endosc. 2021 Jul;94(1):133-144. 【全文链接】 PMID: 33221323 DOI: 10.1016/j.gie.2020.11.012
