Guardian Caps - Are the soft-shelled football helmet covers effective at limiting head injuries? - ESPN
Biomechanics, Free Full-Text
EXPLAINER: NFL using helmet caps for player safety, research
An Idiot's Guide to the Antonio Brown Helmet Grievance - The Ringer
The N.F.L. is Spinning Damar Hamlin's Near-Death Experience as Good P.R. - Air Mail
The link between head injuries and CTE in football, explained - Vox
Helmet Innovation: More and Better Choices, Fewer Concussions
In Brawl For Seau Brain, a Proxy War Over Concussion Science
EXPLAINER: NFL using helmet caps for player safety, research