NFL hopes to reduce head injuries with helmet experiment
High school football teams go soft in the fight against brain injuries
NFL Releases Concussion Data After Use of 'Guardian Caps' During Offseason - Sports Illustrated
Puffy, spongy Guardian Caps could help curb NFL head injuries - The Washington Post
High school football teams go soft in the fight against brain injuries
For Giants and the NFL, it's the Summer of Guardian Caps - Newsday
Guardian Caps', NFL's Most Recent Attempt At Preventing Head Injuries
The story behind those soft-shell puffy Guardian Caps players have been wearing
NFL training camps: Guardian Cap players are wearing over helmets, why
NFL training camps: Guardian Cap players are wearing over helmets, why
Coverage of the NFL in Guardian Caps
[Smith] NFL says positions wearing Guardian Caps saw 52% decrease in concussions : r/nfl
Guardian Caps: Why some NFL players are wearing them in training camps
NFL report: concussions dropped 50 PERCENT when players wore new 'Guardian Caps' over the summer
Why Chiefs players are wearing special foam caps over helmets