RT Journal Article SR Electronic T1 Population preventable fraction of bicycle related head injuries JF Injury Prevention JO Inj Prev FD BMJ Publishing Group Ltd SP 78 OP 78 DO 10.1136/ip.7.1.78 VO 7 IS 1 A1 B Hagel A1 J-F Boivin YR 2001 UL http://injuryprevention.bmj.com/content/7/1/78.1.abstract AB