Altoona Curve honors Pirates legend Roberto Clemente, retires No. 21
Roberto Clemente Day to Be Held Throughout MLB on Thursday – NBC Bay Area
Remembering the life of #21 on Roberto Clemente Day
Here's why it would be a bad idea for MLB to retire Roberto Clemente's No. 21
Curve to retire No. 21 in honor of Pirates OF Roberto Clemente on July 21, Sports
Roberto Clemente remains Latino legend 50 years after death
Roberto Clemente, PDF, Major League Baseball
Retire Twenty One
Curve Set to Retire No. 21 In Honor of Roberto Clemente