Butting heads over bicycle helmets.
Wilhelm
W
Kreyes
D000328:Adult; D001642:Bicycling / Q000293:injuries* / Q000331:legislation & jurisprudence*; D002170:Canada; D002648:Child; D006260:Head Protective Devices / Q000706:statistics & numerical data*; D006801:Humans; D010349:Patient Compliance / Q000523:psychology*; D017751:Safety Management / Q000331:legislation & jurisprudence* / Q000592:standards