How Helmets Have Evolved to Prevent Football Concussions - Chester County Hospital
Laboratory Evaluation of Shell Add-On Products for American Football Helmets for Professional Linemen
Making football helmets safer to prevent concussions
Football Concussions: Prevention, Diagnosis & Recovery
Helmet evolution to reduce concussions visits SEC
This Helmet Will Save Football. Actually, Probably Not. - The New York Times
New helmet design can deal with sports' twists and turns
Laboratory Evaluation of Shell Add-On Products for American Football Helmets for Professional Linemen