NFL hopes to reduce head injuries with helmet experiment
Guardian cap' to prevent head injuries mandated for practices, CFL says
Guardian Caps: Why some NFL players are wearing them in training camps
What is the Q Collar, the device NFL players are wearing around their necks
Why are some Titans players wearing Guardian Caps during training camp?, Titans
NFL players wear Guardian Caps to reduce head trauma during training camp
Guardian Caps - Are the soft-shelled football helmet covers effective at limiting head injuries? - ESPN
It's time the NFL made Guardian Caps mandatory
Oklahoma Sooners Continue to be Proactive in Player Safety With Guardian Caps - Sports Illustrated Oklahoma Sooners News, Analysis and More
Anything we can do to protect them: East Clarendon uses Guardian Caps to protect against concussions - The Sumter Item