Roberto Clemente's death 50 years ago forever changed his son, a former Phillies minor leaguer
Roberto Clemente Day: Pirates and Mets wear 21
For Many Latino Players, Roberto Clemente's Number Is Off Limits, Too - The New York Times
It's time for Roberto Clemente's No. 21 to be retired across baseball - Bucs Dugout
Should Roberto Clemente's Number 21 be Retired Across all of the MLB?
Major League Baseball marks Roberto Clemente Day with ceremony at Citi Field - ESPN
Retire No. 21 for Roberto Clemente - Our Esquina
Outside The Confines: Everyone wore 21 - Bleed Cubbie Blue
Clemente's #21 will not be retired across MLB despite report