Past Time leather football helmets
Impact test comparisons of 20th and 21st century American football helmets in: Journal of Neurosurgery Volume 116 Issue 1 (2012) Journals
Edmonton Seahawks added a new photo. - Edmonton Seahawks
Past Time leather football helmets
Ace Parker, Pro Football Hall of Famer From Leather-Helmet Days, Dies at 101 - The New York Times
The Football Helmet timeline
The History of The Football Helmet timeline
The Evolution of Football Helmets
Leatherhead to Radio-head: The Evolution of the Football Helmet, Arts & Culture
History of The Football Helmet - Atavus