Eriksen et al. 2015, p. 47. Eriksen, Micahel; Mackay, Judith; Schluger, Neil; Gomeshtapeh, Farhad Islami; Drope, Jeffery (2015). The Tobacco Atlas(PDF) (Fifth ed.). Atlanta: American Cancer Society. ISBN978-1-60443-235-0. Archived from the original(PDF) on 16 October 2018. Retrieved 17 June 2017.
Eriksen et al. 2015, p. 47. Eriksen, Micahel; Mackay, Judith; Schluger, Neil; Gomeshtapeh, Farhad Islami; Drope, Jeffery (2015). The Tobacco Atlas(PDF) (Fifth ed.). Atlanta: American Cancer Society. ISBN978-1-60443-235-0. Archived from the original(PDF) on 16 October 2018. Retrieved 17 June 2017.