Textbook of Gastroenterology . 5th ed .Harrison ’ s Principles of Internal Medicine . 17th edition .RichardG Long,Brian B Scott .胃肠与肝脏病学.钱家鸣,孙钢,译.新加坡:Elsevier Pte . Ltd,2008.4 . www . gastroenterology . medscape . com. ......