2[2]Lay CS, Tsat YT, Teg CY, et al. Endoscopic variceal ligation in prophylaxis of first bleeding in cirrhotic patients with high - risk esophageal varices. Hepatology, 1997; 23:1346 ～ 1350
3[7]Kassem AM, Salama ZA, Rosch T. Endoscpic ultrasonography in portal hypertension. Endoscopy, 1997;29:394～406
