This is the unofficial document that's actually guiding NFL refs
How much money do NFL referees make?
Ron Torbert's Salary: How Much Does a Super Bowl Ref Make?
NFL female referees: How many are there and what do they make per
Whispering in the ear of NFL referees - ESPN - NFL Nation- ESPN
How Much Does an NFL Referee Make?
How much do NFL referees make?
Tony Corrente's salary: How much does NFL referee make?
Why do NFL referees wear stripes?
Super Bowl ref salaries: How much do Super Bowl referees make?