TY - JOUR T1 - Race and preterm birth rates in North America JF - Canadian Medical Association Journal JO - CMAJ SP - 13 LP - 14 DO - 10.1503/cmaj.151160 VL - 188 IS - 1 AU - Russell S. Kirby Y1 - 2016/01/05 UR - http://www.cmaj.ca/content/188/1/13.abstract ER -