Best Yankees players by uniform number
What other unused uniform numbers should the Yankees give out? - Pinstripe Alley
Yankees report cards: Lots of D's and F's for franchise's worst club in decades
Best Yankees players by uniform number
Yankees retire Paul O'Neill's No. 21 jersey, Cashman booed
The Yankees Retire Paul O'Neill's Number 21 - The New York Times
Bill Russell's No. 6 Joins Rare Class of Retired Jersey Numbers - The New York Times
New York Yankees Retired Numbers - Sports Illustrated
Derek Jeter returns to the Bronx to have his number retired - New York Amsterdam News
We need to talk about Yankees un-retiring numbers again
Yankees retire Paul O'Neill's No. 21 jersey - NBC Sports