NFL medical director asks for patience with DeVante Parker concussion investigation: 'Let's let all the facts emerge' - The Boston Globe
NFL report: concussions dropped 50 PERCENT when players wore new 'Guardian Caps' over the summer
NFL hopes to reduce head injuries with helmet experiment
Could Guardian Caps be used in games? : r/nfl
[Smith] NFL says positions wearing Guardian Caps saw 52% decrease in concussions : r/nfl
A Town's Passion, a Retired Doctor's Concern - The New York Times
NFL hopes to reduce head injuries with helmet experiment
High school football teams go soft in the fight against brain injuries
NFL hopes to reduce head injuries with helmet experiment
2018 Football Guide by Naval Academy Athletic Association - Issuu