The history of chemicals and the football helmet
NFL at 100: Helmets go high tech in quest for player safety
Helmet Laboratory Testing Performance Results
The Football Helmet. Personal Selection, by Brandon Martin
NFL looking to introduce new football helmets - Dawgs By Nature
New Helmet Technology Aimed to Make Football and Other Sports Safer
EXPLAINER: NFL using helmet caps for player safety, research
Why are NFL players wearing padding on helmets at training camp?
Leatherhead to Radio-head: The Evolution of the Football Helmet
Guardian Caps - Are the soft-shelled football helmet covers
Guardian Cap - Soft-Shell Protective Helmet Cover
First look at each new alternate helmet for the 2022 NFL season