On the Yankees, retired numbers and a solution in search of a problem
Who were the first and last Yankees players to wear the retired numbers? - Pinstripe Alley
The second-best Yankee to wear each retired number - Part One - Pinstripe Alley
Yankees retired numbers and the baseball legends who wore them
Yankees to retire Paul O'Neill's No. 21 jersey this summer - Newsday
Number 21 Continues to Remain Sacred to the New York Yankees, News, Scores, Highlights, Stats, and Rumors
Uniform numbers for Yankees coaches, managers could soon be thing of the past due to numbers shortage
What the Yankees' uniform number crunch could cost MLB's managers and coaches - The Athletic
Yankees Retired Numbers - Who Are The 22 Yankees Who Wore Them