TY - JOUR T1 - In memoriam Ursus JF - Canadian Medical Association Journal JO - CMAJ SP - 753 LP - 753-a DO - 10.1503/cmaj.1070094 VL - 177 IS - 7 AU - Karen Tipler MD Y1 - 2007/09/25 UR - http://www.cmaj.ca/content/177/7/753.2.abstract ER -