NFL hires 21 full-time officials – Football Zebras
A Referee in Michigan was the First Ever to Wear 'Zebra Stripes'
Referee who threw controversial flag in Steelers-Chiefs game reportedly gets the Super Bowl
Ten Years Later, the Failed Lessons From the Fail Mary - The Ringer
Football Zebras - Analysis and commentary of the NFL's officials and the calls they make
What numbers will the new NFL officials receive? – Football Zebras
Preseason referee auditions are back – Football Zebras
Week 18 referee assignments – Football Zebras
Preseason officiating: no referee tryouts, no development officials, no 8th official experiments planned – Football Zebras
Preseason week 2 referee assignments – Football Zebras
Week 4 referee assignments – Football Zebras
December 2015 – Football Zebras
When N.F.L. Zebras Chat With Lions and Giants and Bears - The New York Times