MLB's Pirates will honor Roberto Clemente by wearing his number
Pirates will honor Roberto Clemente by wearing his No. 21 on their jerseys - ESPN
MLB allows more players to wear No. 21 to honor Roberto Clemente – NBC Sports Chicago
Yankees help pay tribute to former Pirates great Roberto Clemente - Newsday
Here's why it would be a bad idea for MLB to retire Roberto Clemente's No. 21
MLB's Pirates To Honor Roberto Clemente By Wearing His Number
All Pirates Wearing #21, Rest of MLB Wears Patches in Honour of Roberto Clemente – SportsLogos.Net News
Pittsburgh Pirates each don No. 21 to honor Roberto Clemente - ESPN
For the 'Great One'; Pirates, MLB honor Roberto Clemente