Guttmann, Astrid, Ruth Blackburn, Abigail Amartey, Limei Zhou, Linda Wijlaars, Natasha Saunders, Katie Harron, and Ruth Gilbert. 2018. “Mortality of Mothers With Opioid-Use During Pregnancy: An International Comparison Using Linked Mother-Baby Records for England and Ontario”. International Journal of Population Data Science 3 (4). https://doi.org/10.23889/ijpds.v3i4.916.