If your looking for some references for letters, there is a ton of information on the Center for Disease and Prevention website.
Make sure you check out all of the subcategories.
Smoking and Tobacco Use :: Fact Sheets :: Adult Data :: Office on Smoking and Health (OSH) :: CDC
Make sure you check out all of the subcategories.
Smoking and Tobacco Use :: Fact Sheets :: Adult Data :: Office on Smoking and Health (OSH) :: CDC
