Roberto Clemente Day: Pirates and Mets wear 21
Remembering Roberto Clemente as a Black man who fought against racial injustice - Los Angeles Times
Pirates to wear No. 21 on Sept. 9 to honor Roberto Clemente - NBC Sports
MLB expands list of who can wear No. 21 to honor Roberto Clemente on Sept. 15 - ESPN
Remembering Roberto Clemente
Roberto Clemente, Pittsburgh's Hero
Roberto Clemente's legacy celebrated in N.Y., Puerto Rico
MLB celebrates Roberto Clemente Day, ceremony at Citi Field
Roberto was our brother': Dave Parker recalls first Pirates spring training after Clemente's death
Introducing: The Oris Roberto Clemente Limited Edition - Hodinkee
Roberto Clemente's No. 21 is 'retired in our hearts' but not on most MLB rosters - The Athletic
Roberto Clemente's death 50 years ago forever changed his son, a former Phillies minor leaguer