Oldest Sports Teams in the US - State by State [MAP] : r/sports
Single-Digit Jerseys Should Be the NFL's Most Exclusive Club - The Ringer
Every MLB team's retired numbers
NBA Teams With the Most Retired Numbers
NBA Teams With the Most Retired Numbers
Retired number - Wikipedia
Bill Russell's No. 6 Joins Rare Class of Retired Jersey Numbers - The New York Times
List of National Football League retired numbers - Wikipedia
2010-11 Limited Retired Numbers Silver Spotlight #16 Henri Richard/49
List of National Football League retired numbers - Wikipedia