RT Journal Article SR Electronic T1 Gastrointestinal cancer: radiation therapy JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 341 OP 341 DO 10.1136/gut.32.3.341 VO 32 IS 3 A1 Norman M Bleehan YR 1991 UL http://gut.bmj.com/content/32/3/341.1.abstract AB