Pirates to wear No. 21 on Sept. 9 to honor Roberto Clemente –
Roberto Clemente Day
21 things you should know on Roberto Clemente Day
Roberto Clemente facts most don't know: Part 2–Dr. Martin Luther King, Jr. and Vic Power – mlbblogger
Comunidad 21 - Un día como hoy, en el 1955 debutó el mejor
Roberto Clemente remains Latino legend 50 years after death
21 fascinating facts about Roberto Clemente
Roberto Clemente, Biography, Stats, & Facts
No gentle saint
Roberto Clemente honored 50 years after Hall of Fame induction
21 Facts You May Not Know About Roberto Clemente on the Anniversary of His Debut, News, Scores, Highlights, Stats, and Rumors
Clemente, the Double Outsider - The New York Times
Graphic Novel Resources: 21 The Story of Roberto Clemente