RT Journal Article SR Electronic T1 Urease induced calcium precipitation by Helicobacter species may initiate gallstone formation JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 1678 OP 1679 DO 10.1136/gut.2006.098319 VO 55 IS 11 A1 Belzer, C A1 Kusters, J G A1 Kuipers, E J A1 van Vliet, A H M YR 2006 UL http://gut.bmj.com/content/55/11/1678.abstract AB