Roberto Clemente Day Serves as Another Reminder to Retire No. 21
50 years after Roberto Clemente's death is time of introspection for Puerto Rican baseball
MLB's Puerto Rican-born players honor Roberto Clemente by wearing 21
ESPN: MLB to allow Pirates, Puerto Rican players, award nominees to wear No. 21 on Roberto Clemente Day
Living out the legacy: Curve retire No. 21 as reminder of Clemente's greatness
Retire Twenty One
Should Roberto Clemente's Number 21 be Retired Across all of the MLB?
Roberto Clemente in Retrospect - Pittsburgh Quarterly
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ROBERTO CLEMENTE RETIRED JERSEY NUMBER 21 PATCH - PUERTO RICO FLAG EDITION
For Many Latino Players, Roberto Clemente's Number Is Off Limits, Too - The New York Times
MLB celebrates former Pirates great Roberto Clemente Day
Honor a Legacy, Not a Number - The New York Times
New Jersey politicians move to retire Roberto Clemente's No. 21 across all of baseball