Officially, beards are in this season – Football Zebras
NFL Refs: The Stars In Stripes - 60 MINUTES SPORTS Preview - SHOWTIME
How is the color of a referee's uniform defined, in soccer matches, when they aren't wearing all black? - Quora
Congrats on the Kansas City referees on making the super bowl this year : r/Patriots
NFL suffers referee exodus ahead of new season for second straight year - Mirror Online
Why Do Referees Wear Stripes?
Why Do Referees Wear Stripes?
The official story Iowa Now - The University of Iowa
Ever Wonder? Why do Referees Wear Stripes?
NFL100: Before they were zebras, they were … candy canes? – Football Zebras
Crown Sport Goods, Men's Official Black & White Striped Referee /Umpire Jersey, Pro-Style Uniform