What year was the Detroit Lions team formed?
History of the Detroit Lions
McDonough, Will (1994). 75 Seasons: The Complete Story of the National Football League. Atlanta: Turner Publishing, Inc. ISBN1-57036-056-1
Peterson, Robert W. (1997). Pigskin: The Early Years of Pro Football. New York: Oxford University Press. ISBN0-19-507607-9
Willis, Chris (2010). The Man Who Built the National Football League: Joe F. Carr. Lanham, Maryland: Scarecrow Press, Inc. ISBN978-0-8108-7669-9