List of National Football League retired numbers - Wikipedia
How Many Jersey Numbers have been Retired in the NFL?
Retired Numbers for Each NFL Team
Every MLB team's retired numbers
Cardinals wide receiver A.J. Green announces his retirement from NFL via social media
What are some “unofficially” retired numbers that are not reissued? : r/nfl
List of National Football League retired numbers - Wikipedia
List of National Football League retired numbers - Wikipedia
Tom Brady is un-retiring just 40 days after leaving the Bucs : NPR
Carl Nassib, first active NFL player to come out as gay, announces retirement from football
Kent Somers: Digging Out Of The 0-2 Hole In The NFL
Chargers to Retire Numbers of Pro Football Hall of Fame Receiver Charlie Joiner and Pro Football Hall of Fame Tight End Kellen Winslow
The Yankees Retire Paul O'Neill's Number 21 - The New York Times