NFL to prohibit use of certain helmets for 1st time – The Denver Post
Riddell's Newest Helmet – The Concussion Blog
New NFL quarterback helmet aims to help combat concussion effects
The VICIS ZERO1: Engineering a Safer Football Helmet - GrabCAD Blog
NFL's safest helmet ever may not be enough to stop concussions
Brilliance in Marketing: Top Football Helmet Brands
A High-Tech Helmet Protects Football Players from Concussions - Seattle magazine
Vicis high-tech helmets take top 3 spots in NFL's annual performance ranking of equipment – GeekWire
Design and Virtual Testing of American Football Helmets–A Review
With concussions at forefront of minds, helmet designs more important
Big Changes To NFL Helmets Coming Soon? - Daily Norseman
Youth Football Helmet Ratings
NFL launches youth safety, helmet program
CTE found in 345 of 376 former NFL players studied