NFL Relaxes Restrictions on Jersey Numbers - The New York Times
Super Bowl LIV: How NFL Measures First Downs Is Primitively Low-Tech
Column: NFL officials make far too many mistakes, and it's worse in the playoffs - The San Diego Union-Tribune
How do the NFL's new overtime rules affect the Patriots?
Who Are the NFL's Best, Worst Refs? | News, Scores, Highlights, Stats, and Rumors | Bleacher Report
Ump Attire - The NFL is back! Let's wish our officials... | Facebook
Why do college football referees have an 'S' on their uniform? - Quora
Law 5 - The Referee
NRL referees should take step back in finals
NFL100: Before they were zebras, they were … candy canes? | Football Zebras
Ed Hochuli, N.F.L. Referee, Has Long Had Fan Support - The New York Times
Officials' Responsibilities & Positions | NFL Football Operations
US referee numbers are plunging and aggression is to blame | Referees | The Guardian
What do the letters stand for on the back of football referees' shirts? - Quora
Why Do NFL Referees Have Numbers on Their Uniforms?
Why do college football referees have an 'S' on their uniform? - Quora
What are the black string-like things football referees wear on their hands for? - Quora
Why Football Referees Have Letters & Numbers – vIQtory Sports
Why Football Referees Have Letters & Numbers – vIQtory Sports
Yeah, the O-line is important, but referees are Tom Brady's best friends
Football League referees will clamp down on time-wasting and punish dissent next season | Daily Mail Online
College football referees have an impossible job. Here's why - Sports Illustrated
Ask Farmer: Why do NFL referees have numbers? - Los Angeles Times
Why Football Referees Have Letters & Numbers – vIQtory Sports
All the Gear Super Bowl 50 Refs Will Use to Call the Game | WIRED
Empty stadium impact on referee decisions, home field advantage - Sports Illustrated
Ask Sam Farmer: Are there throwback uniforms for NFL officials? - Los Angeles Times
NFL Officials: Preparing for Success | NFL Football Operations
New NFL font
