RT Journal Article SR Electronic T1 Primary care electronic medical records: a new data source for research in Canada JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP 239 OP 240 DO 10.1503/cmaj.140473 VO 187 IS 4 A1 Richard Birtwhistle A1 Tyler Williamson YR 2015 UL http://www.cmaj.ca/content/187/4/239.abstract