Guardian Caps - Are the soft-shelled football helmet covers
Puffy, spongy Guardian Caps could help curb NFL head injuries
NOCSAE Finalizes First-Ever Football Helmet Standard to Address
Can a Better Football Helmet Save Your Kid's Brain? - Washingtonian
SAFR Sports – Safer through Science
More padding the issue of concussions and better helmets
More padding the issue of concussions and better helmets
Flexible NFL helmet aims to reduce head injuries
Making football helmets safer to prevent concussions