Wu, Michael, BCIT School of Health Sciences, Environmental Health, Helen Heacock, Maria Tirado, and Fred Shaw. “Presence of Nicotine in Marketed Nicotine-Free E-Liquids for Electronic Cigarettes”. BCIT Environmental Public Health Journal (May 1, 2017). Accessed April 18, 2024. https://journals.bcit.ca/index.php/ehj/article/view/88.