2021 NFL rule changes guide - What to expect from more replay help, jersey number flexibility, more - ESPN
NFL Kickoff 2021: Fox Sports Enhances NFL Coverage with More Super Slo-Mo, Remote Workflows
NFL replay rules could reportedly change dramatically in 2021
NFL officiating is under fire, putting the Super Bowl crew in the spotlight - The Athletic
NFL Instant Replay Process
Official (gridiron football) - Wikipedia
Replay review in gridiron football - Wikipedia
College Football Rule Changes for 2021 - The New York Times
Following Protocol: Inside NFL's Player Safety Measures
NFL's instant replay officials have new powers, but owners weren't interested in other major rules changes - The Boston Globe
NFL May Soon Split Instant Replay Decisions Between NYC and LA
The NFL's 3 changes under the hood of replay that could have mixed results – Football Zebras
TRANSCRIPT: ESPN Analyst Kirk Herbstreit Discusses the 2021 NFL Draft Quarterback Class and Previews His New QB21 with Kirk Herbstreit Series - ESPN Press Room U.S.
Nick Chubb's injury shows why running backs want more money — and why the NFL won't pay them