San Francisco - HELMET HISTORY
San Francisco 49ers, American Football Wiki
2012 Tennessee Tech Football Guide by Tennessee Tech Sports Information - Issuu
San Francisco 49ers Facts for Kids
2011 Georgia Tech Football Bowl Notes by GTAthletics - Issuu
2020.40.1 - Helmet Bartlett History Museum
San Francisco - HELMET HISTORY
San Francisco 49ers, American Football Wiki
2013 SMU Football Factbook by SMU Athletics - Issuu
TUSKEGEE UNIVERSITY FOOTBALL - Tuskegee University Athletics
Joe Montana & Jerry Rice Autographed San Francisco 49ers Mini Helmet w – Score Authentics
Los Angeles Rams: Most Up-to-Date Encyclopedia, News & Reviews
2010 Michigan State Football Media Guide by Ben Phlegar - Issuu
Lee Patton (2004) - WVU Sports Hall of Fame - West Virginia University Athletics
The History of The Football Helmet timeline