Before Brooklyn: the secret heroes who helped break baseball's color barrier, MLB
Baseball Hall of Fame Will Create New Exhibit on Race - The New York Times
The Negro Leagues were added to official MLB records. But don't expect major changes in the record books.
The Woman Who (Maybe) Struck out Babe Ruth and Lou Gehrig, History
Baseball Reference Adds Negro League Stats - The New York Times
The Negro Leagues are major leagues — but merging their stats has been anything but seamless - The Athletic
Polo Grounds - Wikipedia
New York Times Custom Baseball Book – The New York Times Store
MLB Recognizes Negro Leagues As 'Major League' : NPR