Yankees to retire Paul O'Neill's No. 21: See the complete list of retired numbers
Yankees retired numbers: A look at all of the jersey numbers
Paul O'Neill, Baseball Wiki
Paul O'Neill Yankees No. 21 retired
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The Yankees Retire Paul O'Neill's Number 21 - The New York Times
Paul O'Neill's No. 21 to be retired by Yankees
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Paul O'Neill will finally have number retired by Yankees
Paul O'Neill Number Retirement before Yankees vs. Blue Jays on
Paul O'Neill Number Retirement before Yankees vs. Blue Jays on