RT Journal Article SR Electronic T1 13C-urea breath test for Helicobacter pylori infection. JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 551 OP 552 DO 10.1136/gut.32.5.551-a VO 32 IS 5 A1 G D Bell A1 K Powell A1 J Weil A1 G Harrison A1 S Brookes A1 S Prosser YR 1991 UL http://gut.bmj.com/content/32/5/551.2.abstract AB