Trends in e- cigarette brands, devices and the nicotine profile of products used by youth in England, Canada and the USA: 2017-2019. - Hammond, David; Reid, Jessica L.; Burkhalter, Robin; O'Connor, Richard J.; Goniewicz, Maciej L.; Wackowski, Olivia A.; Thrasher, James F.; Hitchman, Sara C. (Tobacco Control, 2023)