Head injuries, helmets, cycle lanes, and cyclists.

@article{Simpson1988HeadIH,
  title={Head injuries, helmets, cycle lanes, and cyclists.},
  author={A. Hamish R. W. Simpson and Paul S Unwin and Ian W. Nelson},
  journal={British medical journal},
  year={1988},
  volume={296 6630},
  pages={
          1161-2
        }
}