Buckley: Who's next? Examining the state of Boston's retired numbers - The Athletic
Retired number - Wikipedia
A number of nuggets about retired numbers around the Major League
Joe Namath would allow Aaron Rodgers to wear retired number with Jets
The Seattle Mariners need to retire number 51 for two Hall of Famers
Has the NFL Ever Retired a Player's Jersey Number League-Wide?
The second-best Yankee to wear each retired number - Part One - Pinstripe Alley
Every MLB team's retired numbers
List of Major League Baseball retired numbers - Wikipedia
Which pro sports teams have the most retired numbers?
Retired number - Wikipedia
Da Greats: Retired Chicago Bears Jersey Numbers - The Chicago Audible