A scoring system to predict the risk of postoperative complications after laparoscopic liver resection in elderly hepatocellular carcinoma patients - LEE, Boram; CHO, Jai Young; HAN, Ho-Seong; YOON, Yoo-Seok; LEE, Hae Won; LEE, Jun Suh; KIM, Munhwan (Annals of hepato-biliary-pancreatic surgery, 2021)