1. http://www.nbcnews.com/health/health-news/only-15-percent-u-s-adults-now-smoke-cdc-finds-n579646
  2. https://www.cdc.gov/tobacco/data_statistics/fact_sheets/adult_data/cig_smoking/index.htm
  3. http://www.lung.org/our-initiatives/tobacco/reports-resources/sotc/by-the-numbers/10-worst-diseases-smoking-causes.html?referrer=https://www.google.com/
  4. https://www.nhlbi.nih.gov/health/health-topics/topics/smo
  5. http://herb.co/2017/02/12/cannabsiheart/
  6. http://www.nytimes.com/health/guides/disease/coronary-heart-disease/diagnosis.html
  7. https://www.nhlbi.nih.gov/health/health-topics/topics/cad/treatment
  8. http://www.cnn.com/2016/08/08/health/marijuana-use-doubles-gallup-poll/index.html
  9. http://www.drugfreeworld.org/drugfacts/drugs/marijuana.html
  10. https://www.vice.com/en_us/article/gv3jb3/weed-might-put-you-at-greater-risk-for-heart-attack-or-stroke-says-study
  11. http://www.acc.org/latest-in-cardiology/articles/2016/09/22/08/58/marijuana-and-coronary-heart-disease
  12. http://www.texasheart.org/HIC/Topics/HSmart/smoking.cfm
  13. https://www.cdc.gov/tobacco/data_statistics/sgr/50th-anniversary/pdfs/fs_smoking_CVD_508.pdf
  14. https://www.drugabuse.gov/publications/drugfacts/electronic-cigarettes-e-cigarettes
  15. https://www.centeronaddiction.org/e-cigarettes/about-e-cigarettes/10-surprising-facts-about-e-cigarettes
  16. https://www.livescience.com/57735-e-cigarette-heart-risks.html
  17. https://tobacco.ucsf.edu/first-evidence-e-cig-use-increases-heart-attacks-independent-effect-smoking-cigarettes
  18. https://www.theverge.com/2017/2/1/14460996/e-cig-vaping-risk-heart-disease-health-jama-study