NFL approves alternate helmets beginning in 2022
John Harbaugh Reacts to NFL's New Kickoff and Helmet Rules
The 2023 Uni Watch NFL Season Preview - by Paul Lukas
NFL teams are using a new, safer helmet — the Vicis Zero1
Seeking to reduce head contact, NFL mandates use of Guardian Cap helmet for early portion of training camp - ESPN
This Helmet Will Save Football. Actually, Probably Not. - The New York Times
Helmet Laboratory Testing Performance Results
The safest helmet in football: What's inside the NFL's newest headgear
Leatherhead to Radio-head: The Evolution of the Football Helmet, Arts & Culture
Flag Football Equipment - NFL FLAG
Denver Broncos: Light blue helmets might be allowed in 2021
Tom Brady: Patriots QB speaks on NFL helmet change, has no choice
Helmet Innovation: More and Better Choices, Fewer Concussions