RT Journal Article SR Electronic T1 Cost benefit of out of hours endoscopy: the options JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 282 OP 282 DO 10.1136/gut.2010.227629 VO 60 IS 2 A1 Heymann, Tim YR 2011 UL http://gut.bmj.com/content/60/2/282.1.abstract AB