https://www.cdc.gov/tobacco/data_statistics/sgr/2004/posters/20mins/index.htm
https://www.cdc.gov/tobacco/data_statistics/sgr/50th-anniversary/pdfs/fs_smoking_respiratory_508.pdf
https://www.cdc.gov/tobacco/campaign/tips/stories/shawn.html
https://www.cdc.gov/tobacco/data_statistics/fact_sheets/health_effects/effects_cig_smoking/index.htm
https://www.cdc.gov/tobacco/campaign/tips/stories/amanda.html
https://www.cdc.gov/tobacco/campaign/tips/stories/beatrice.html
https://www.cdc.gov/tobacco/campaign/tips/stories/roosevelt.html
https://www.cdc.gov/tobacco/basic_information/e-cigarettes/index.htm