Source: No break-in process for new NFL helmets - ESPN
NFL safety: How VICIS' position-specific helmets have become all the rage - The Athletic
Helmet Innovation: More and Better Choices, Fewer Concussions
NFL hopes to reduce head injuries with helmet experiment
NFL to test new position-specific helmet designed for linemen - ESPN
Football Helmets for 2017 - Riddell and Schutt Helmet Technology
Safety first: Lopers to wear padded caps in practice to prevent concussions
The safest helmet in football: What's inside the NFL's newest headgear
Sherwood Foundation buys data-tracking helmets for every OPS high school football player