Why are MLB players wearing No. 42 jerseys today?
Los Angeles Dodgers to retire Fernando Valenzuela's No. 34 jersey
Dave Stewart wore A's No. 34 with Rollie Fingers' blessing. Now both will have it retired
Baseball Retired Numbers - University of Michigan Athletics
MLB retired numbers include 10 for state players
Jaime Jarrín Wants Dodgers To Retire Fernando Valenzuela's No. 34
MLB players to wear No. 42 — in Dodger blue — for 75th anniversary of Jackie Robinson's big league debut
Dodgers are finally retiring Fernando Valenzuela's number - Los Angeles Times
Jackie Robinson Day - Wikipedia