Design and Virtual Testing of American Football Helmets–A Review
The Evolution of Football Helmets, by Jose Diaz
Design and Virtual Testing of American Football Helmets–A Review
The Evolution of Football Helmets
Leatherhead to Radio-head: The Evolution of the Football Helmet, Arts & Culture
Football helmet - Wikipedia
The Evolution of Football Helmets, by Jose Diaz
Researchers test old-style leather helmets vs. modern ones and found leather performed as well, better in some aspects. Conclusion: Football helmets need to be softer. : r/nfl
Delaware State University Archives and Special Collections: Helmets Through History