http://www.bmj.com/content/346/bmj.f2674 a paper No evidence--none--that helmets reduce injuries safety Studie der Universität von Toronto No evidence--none--that helmets reduce injuries http://www.bmj.com/content/346/bmj.f2674 no different im "British Medical Journal" veröffentlichte Studie BMJ: Dennis et al, 2013 Une étude protective gear recent study Canadian study Zahlen No evidence--none--that helmets reduce injuries British Medical Journal article a paper the British Medical Journal article BMJ, Dennis et. al. did not reduce http://www.bmj.com/content/346/bmj.f2674 no different British Medical Association study Canadian helmet legislation in the BMJ states señala estudio canadiense lire en ligne British Medical Association Canadian Provinces Canadian helmet legislation in the BMJ states señala