Monument Park at Yankee Stadium - Attractions - Baseball Life
Paul O'Neill on No. 21 retirement Yankees
US Bronze Created the Plaques of Yankees' Monument Park
Yankees history: Eddie Bockman's four games wearing Babe Ruth's #3 - Pinstripe Alley
Yankee Stadium and Monument Park - Clio
Yankees retired numbers - Newsday
The Babe Ruth plaque in Monument Park at Yankee Stadium
Yankees, Eager to Retire Numbers, Subtract Options for Current Players - The New York Times
46 years ago, Mickey Mantle got a spot in Monument Park -- which was in play in center field
Monument Park (Yankee Stadium) - Wikipedia
Will Derek Jeter's No. 2 be the final retired Yankee jersey?