SF Giants' Ortiz, García to wear No. 21 on Roberto Clemente Day
MLB celebrates former Pirates great Roberto Clemente Day
Pittsburgh Pirates to wear No. 21 on sept 9 to honor Roberto Clemente
MLB's Puerto Rican-born players honor Roberto Clemente by wearing 21
Campaign To Retire Roberto Clemente's No. 21 Throughout MLB Gains Traction
Puerto Rican players follow Pirates' push to wear No. 21, celebrate Roberto Clemente
Should MLB retire Roberto Clemente's jersey number?
Pirates walk off on Roberto Clemente Day as push to retire his No. 21 continues
Roberto Clemente Foundation 21
Carlos Delgado says MLB should retire Roberto Clemente's No. 21