Uniform number (Major League Baseball) - Wikiwand
Have the Yankees taken retired numbers too far?, Bronx Pinstripes
Yankees Retire Paul O'Neill's No. 21 Jersey, Cashman Booed - Bloomberg
Why don't the Miami Marlins have any retired numbers?
Yankees retire Paul O'Neill's No. 21 jersey
Should San Diego Padres Unretire #6?
Yankees news: Yanks trade for pitcher after Opening Day win - Pinstripe Alley
New York Yankees: 5 numbers that need to be un-retired
New York Yankees retired numbers New york yankees, Yankees retired numbers, Yankees
Clint Frazier reportedly asked the Yankees if they would un-retire Mickey Mantle's No. 7
Why The Cubs Need More Retired Numbers - Bleed Cubbie Blue