From Head To Toe And More - Mississippi State
NFL hopes to reduce head injuries with helmet experiment
Guardian Caps Guardian Sports
Unprecedented Rate Of Improvement Stimulated In Helmet Industry, New Standard Set For 'Top-Performing' Helmet Models Worn By NFL Players
EXPLAINER: NFL using helmet caps for player safety, research
Riddell's Axiom could be breakthrough helmet for football
NFL players experiment with 'Guardian Caps' to protect heads
The Coat of Arms Added Protection or False Security: Football Tests New Guardian Caps to Prevent Concussions
College programs take proactive approach to helmet safety, All OU Sports
Guardian Cap Results: “Exceeded Our Expectations”
Guardian Caps - Are the soft-shelled football helmet covers effective at limiting head injuries? - ESPN
Bellmore-Merrick athletics debuts new guardian caps, Herald Community Newspapers
Experimental Helmet Aims To Fix Football
Exactly How Dangerous Is Football?
The N.F.L. Struggles to Tackle Its Latest Problem: Tackling - The New York Times