Varsity Football Helmet Ratings
Football Helmets and Concussion: Equaling the Playing Field - Advancing Your Health
New Stanford-Developed High-Tech Helmets Could Protect Football Players From Debilitating Concussions
Study: Newer Football Helmets Could Slash Concussion Risks
Next gen hard hats give better protection against head injury : Shots - Health News : NPR
Concussions from top-of-head impact 'more severe'
New Riddell SpeedFlex football helmet pits technology vs. concussions
Guardian Caps - Are the soft-shelled football helmet covers effective at limiting head injuries? - ESPN
NFL: Concussions dropped by more than 50% among players who wore Guardian Caps during summer
Guardian Caps Guardian Sports
Why helmets are no magic bullet for preventing concussions - WHYY
NFL Helmet Manufacturer Warned On Concussion Risk
How are H.S. football helmets tracked & managed? Investigation reveals lack of uniformity
Head Injuries & American Football - Ethics Unwrapped
Large Bubble Helmets Are Guardian Caps, NFL's New Safety Measure