NFL hopes to reduce head injuries with helmet experiment
Eagles Notes: New Guardian Caps get mixed reviews – Delco Times
Guardian Caps Guardian Sports
Saints adjusting to use of Guardian Caps in training camp - Daily Leader
Players, coaches react to mandatory use of Guardian Caps
Get A Load Of These Big Dumb Helmet Helmets
Guardian cap' to prevent head injuries mandated for practices, CFL says
Coverage of the NFL in Guardian Caps
NFL Makes Ruling On Players Wearing Guardian Cap During Game - The Spun: What's Trending In The Sports World Today
NFL says Guardian Caps reduced concussions by more than 50%
Could Guardian Caps be used in games? - NBC Sports