Alex Rodriguez fondly recalls 2001 All-Star tribute to Cal Ripken Jr. – New York Daily News
Detroit Tigers celebrate 21st annual Negro Leagues Weekend this weekend
MLB Clemente Award winners wear his 21 on caps for careers - NBC Sports
MLB celebrates Roberto Clemente Day
Jackie Robinson Day - Wikipedia
Some MLB Players Wearing #21, All Wearing 21 Patches Today for Roberto Clemente Day – SportsLogos.Net News
Tributes pour in for Long Beach boy who died while playing baseball - Newsday
Nats DH Cruz, other Clemente Award winners wear '21' on caps
Blue Jays players, personnel wear No. 21 in honour of Roberto Clemente