"William 'Pop' Gates". The Black Fives Foundation. September 29, 2016. Retrieved May 3, 2021.
books.google.com
Rayl, Susan (2000). "Gates, William ("Pop")". In Kirsch, George B.; Harris, Othello; Nolte, Claire E. (eds.). Encyclopedia of Ethnicity and Sports in the United States. Westport, CT: Greenwood Press. p. 177. ISBN0-313-29911-0.