1. Pedal cyclists, crash helmets and risk;McCarthy, M.;Public Health,1991
2. Road accidents Great Britain 1990: the casualty report;Department of Transport,1991
3. Cyclists need helmets;Bull, J.P.;BMJ,1988
4. When are cyclists going to wear helmets?;Lancet,1988
5. A case-control study of the effectiveness of bicycle safety helmets;Thompson, R.S.; Rivara, F.P.; Thompson, D.C.;N EnglJ Med,1989