EXPLAINER: NFL using helmet caps for player safety, research
What are those helmet pads Chicago Bears offensive linemen have been wearing at practices?
Arizona Cardinals defensive end J.J. Watt not fan of the new league-mandated Guardian Caps on helmets
NFL executive hints that Guardian Caps could eventually be worn in games, along with position-specific helmets
Chicago Bears: Why players are wearing padded helmets
Guardian Cap: What are and why the NFL asks this safety measure in helmets
NFL training camps: Guardian Cap players are wearing over helmets, why
Chicago Bears: Why players are wearing padded helmets
What is the NFL guardian cap and how does it work? – NBC Sports Bay Area & California
NFL's top doctor does not expect Guardian Caps to be worn in games - NBC Sports
NFL CMO Dr. Allen Sills explains importance of mandated guardian caps during training camp
Patriots, rest of NFL wearing cushioned helmet caps at training camp, per new mandate - CBS Boston
Top football helmet maker explores padded covers, report says
Guardian Caps - Are the soft-shelled football helmet covers effective at limiting head injuries? - ESPN