RT Journal Article SR Electronic T1 Supradiaphragmatic perforated duodenal ulcer in a giant hiatus hernia JF Canadian Journal of Surgery JO CAN J SURG FD Canadian Medical Association SP E89 OP E90 VO 51 IS 4 A1 Muhammad Hanif Shiwani A1 Michael P. Thornton YR 2008 UL http://canjsurg.ca/content/51/4/E89.abstract