RT Journal Article SR Electronic T1 Teenage pregnancy: trends, contributing factors and the physician's role JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP 1601 OP 1602 DO 10.1503/cmaj.070352 VO 176 IS 11 A1 Donald B. Langille YR 2007 UL http://www.cmaj.ca/content/176/11/1601.abstract