Roberto Clemente, Pittsburgh's Hero
Roberto Clemente day: Puerto Rican MLB players, Pirates wear No. 21
Sources: MLB letting more players to wear No. 21 for Clemente Day
MLB's Pirates To Honor Roberto Clemente By Wearing His Number
50 Years Later, the Pirates' Lineup of Color Still Resonates - The New York Times
Puerto Rican MLB players can wear number 21 on Clemente Day
Roberto Clemente: More than Latin America's baseball star
For the 'Great One'; Pirates, MLB honor Roberto Clemente – KXAN Austin
MLB celebrates Roberto Clemente Day, ceremony at Citi Field - CBS Pittsburgh
Some MLB Players Wearing #21, All Wearing 21 Patches Today for Roberto Clemente Day – SportsLogos.Net News
Pirates to wear No. 21 on Sept. 9 to honor Roberto Clemente - NBC Sports
Clemente Award winners will have 21 on caps for entire MLB career
Entire Pirates team will wear No. 21 to honor Roberto Clemente