Changes

Tygiel, J. (1983). ''[https://www.amazon.com/gp/product/0195339282/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0195339282&linkCode=as2&tag=dailyh0c-20&linkId=bac520ef0988e0024acf626b39b762ff Baseball's great experiment: Jackie Robinson and his legacy].'' New York: Oxford University Press.

Peterson, R. (1970) ''[https://www.amazon.com/gp/product/0195076370/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0195076370&linkCode=as2&tag=dailyh0c-20&linkId=79f4d2deaf7cd106ab61d688207d3a00 Only the Ball was White: A History of Legendary Black Players and All-Black Professional Teams]'' Englewood Cliffs, N.J.New York, Prentice-HallOxford University Press.