NFL tests coronavirus-limiting masks with N95, surgical material
Could NFL players wear masks during the 2020 season? Lingering coronavirus-related questions - ESPN
NFL suspends all COVID protocols, cites 'encouraging trends'
Novak Djokovic to Play at U.S. Open After COVID-19 Policy Change – SportsTravel
Head Injuries & American Football - Ethics Unwrapped
NFL studying helmet face guard that works like surgical mask
NFL unveils face shields to protect players from coronavirus
The N.F.L. Struggles to Tackle Its Latest Problem: Tackling - The New York Times
Engineers modify football helmet to reduce the spread of COVID-19 - College of Engineering News
What happens when NFL players test positive for COVID-19?
NFL At 100: From head to toe, players equipment has evolved