National Baseball Hall of Fame and Museum ⚾ on Twitter: "Lou Gehrig's #4 was the first number retired by an @MLB team, and it opened the door for other teams to follow
Yankees retired numbers: A look at all of the jersey numbers players cannot wear in the Bronx - CBSSports.com
Ny Yankees | Accessories | Ny Yankees Retired Numbers | Poshmark
New York Yankees: Retiring numbers, plaque ceremonies must end
The case for retiring Graig Nettles' number - Pinstripe Alley