Injury prevention. Bicycle helmet promotion programmes, Canada, Australia, and United States of America.
D001315:Australia / Q000453:epidemiology; D001642:Bicycling / Q000293:injuries; D002170:Canada / Q000453:epidemiology; D006259:Craniocerebral Trauma / Q000209:etiology / Q000517:prevention & control*; D006260:Head Protective Devices / Q000706:statistics & numerical data*; D006801:Humans; D014481:United States / Q000453:epidemiology