Negro League Baseball
Negro Leagues History - Negro Leagues Baseball Museum
SABR Century: 1921 Negro National League – Society for American Baseball Research
Black baseball before the Negro Leagues - Beyond the Box Score
The secret history of black baseball players in Canada's great white north
MLB's inclusion of Negro Leagues stats reframes greatest-player debate
Negro Baseball League Timeline
Negro Baseball Leagues (1920-1950) •
1920 Season- Seamheads Negro Leagues Database