Leatherhead to Radio-head: The Evolution of the Football Helmet, Arts & Culture
Extraordinary Stories From An Ordinary Guy: The The Evolution Of Football Wear Story
History of The Football Helmet - Atavus
The first-ever NFL helmet with a logo was hand-painted by the Rams' Fred Gehrke in 1947 - ABC7 Los Angeles
Classic Helmet Designs for Each NFL Team, News, Scores, Highlights, Stats, and Rumors
Football helmet - Wikipedia
The Broncos' helmet history in photos
The History of the Football Helmet - Brain Injury Law Center
The Evolution of Football Helmets timeline
Best college football helmets: Notre Dame, Michigan, more - Sports Illustrated
Built By Data: NFL Helmet Innovation