Inbox: This was a nice step forward
Why Wisconsin football's Ben Barten is the 'Professor'
NFL hopes to reduce head injuries with helmet experiment
Puffy, spongy Guardian Caps could help curb NFL head injuries - The Washington Post
NFL training camps: Guardian Cap players are wearing over helmets, why
WATCH: Jason Kelce puts on bubble wrap over mandatory NFL Guardian Cap at Eagles training
Could Guardian Caps be used in games? : r/nfl
How a soft-shell helmet is limiting the risk of concussions at Rutgers football camp
Large Bubble Helmets Are Guardian Caps, NFL's New Safety Measure
NFL players experimenting with 'Guardian Caps' to prevent head injuries