Super Bowl 57 Referee Carl Cheffers Analysis, Officiating Trends, and Tendencies
NFL referee appeared to hip-check a player just before throwing controversial, game-changing penalty flag
The Bills were not happy about a 'dirty' hit from Rob Gronkowski - The Boston Globe
Referee explains the do-over in critical moments of Bengals vs. Chiefs
Rams, Patriots fans unhappy with referee assignments for conference championship games
History of the Official NFL Football Operations