From the Centers of Disease Control. Differences in age of smoking initiation between blacks and whites--United States.
D000293:Adolescent; D000328:Adult; D001741:Black or African American; D000367:Age Factors; D005260:Female; D006801:Humans; D008297:Male; D012907:Smoking / Q000208:ethnology*; D014481:United States / Q000453:epidemiology; D044465:White People