Sherman: Slit-film turf at Paycor, other NFL fields must be removed
NFL players union boss wants natural grass after Rodgers injury, Nation
NFLPA says new data shows turf fields still cause more injuries than natural surfaces
NFL data shows recent injury rates same on grass, artificial turf - ESPN
NFL Fields: J.C. Tretter Says New Data Shows 'Large Difference' Between Grass, Turf Surfaces
Why are NFL players pushing the league to switch to grass fields?
Did NFL lie about injury rates on artificial turf? NFLPA president rips Jerry Jones, league for using outlier data
NFLPA calls for league-wide grass fields following Rodgers' injury
Aging artificial turf fields may carry risk of head injuries - The Boston Globe
New data shows NFL injuries in artificial turf stadiums mostly exceed injuries in grass stadiums
NFLPA calling to move all stadium fields to natural grass after Rodgers' injury