Puffy, spongy Guardian Caps could help curb NFL head injuries - The Washington Post
NFL says Guardian Caps reduced concussions by over 50%
NFL: Concussions dropped by more than 50% among players who wore Guardian Caps during summer
NFL fans blast league over Guardian Caps following Jets HC Robert Saleh's criticism
Bellmore-Merrick athletics debuts new guardian caps, Herald Community Newspapers
Could Guardian Caps be used in games? : r/nfl
As NFL mandates Guardian caps in practice, area high school football teams have been using them for years, Sports
NFL says positions wearing Guardian Caps saw 52% decrease in concussions - NBC Sports
Guardian Cap Results: “Exceeded Our Expectations”
The Coat of Arms Added Protection or False Security: Football Tests New Guardian Caps to Prevent Concussions
NFL hopes to reduce head injuries with helmet experiment
NFL introduces Guardian Caps across league to limit number of brain injuries in preseason
Why are NFL players wearing padding on helmets at training camp?