New helmet design can deal with sports' twists and turns
Puffy, spongy Guardian Caps could help curb NFL head injuries - The Washington Post
Football Helmet Misconceptions: Q&A
Guardian Cap - Soft-Shell Protective Helmet Cover : Football Helmets : Sports & Outdoors
How football helmets fail to protect against some of the most dangerous hits in the game - The Verge
Football helmets are creating more problems than they solve
Football Helmets Fail to Prevent All Injuries - CBS News
Schutt F7 VTD Adult Football Helmet - Sports Unlimited
NFL hopes to reduce head injuries with helmet experiment
Super Bowl: How to Make Football Safer
How football helmets fail to protect against some of the most dangerous hits in the game - The Verge