Guardian Caps - Are the soft-shelled football helmet covers effective at limiting head injuries? - ESPN
Football helmet - Wikipedia
2021 Yearbook by Tennessee Titans - Issuu
Explaining the NFL's latest concussion controversy and policy change : NPR
Do you remember the Saints' rookie 'bucket helmet'?, Entertainment/Life
Smart football helmet may help detect concussions
Helmets don't eliminate concussions. It's time for the NFL to ditch them, NFL
This Helmet Will Save Football. Actually, Probably Not. - The New York Times
Anti-Concussion Football Helmets Not Fully Enforced By NFL, NCAA, or U.S. High Schools
Football's dangers, illustrated by one man's brain
The Samoan Way of Football - WSJ