Do MLB players have to wear numbers on their uniforms? - Quora
MLB players to wear #42 Monday to honor Jackie Robinson Day
All MLB Players to Wear No. 42 in Dodger Blue on Jackie Robinson Day
Robinson's 42 in Dodger blue for all uniforms on April 15 - CBS Los Angeles
Book excerpt: The original Jackie Robinson Day at Dodger Stadium - Los Angeles Times
Jackie Robinson Day - Wikipedia
Remembering Jackie Robinson's historic play breaking the color line 75 years ago, Richmond Free Press
Robinson's 42 In Dodger Blue For All Uniforms On April 15
Jackie Robinson Day #42
All of MLB to wear Jackie Robinson's No. 42 in Dodger Blue on April 15 - ESPN