Why Bears legend Walter Payton is greatest NFL player of all time
Was Bears' Dick Butkus the greatest NFL linebacker ever? – NBC Sports Chicago
Walter Payton - Wikipedia
Chicago Bears: A 'Decade-by-Decade History' Book, Chicago News
Best Bears running backs: Payton, then the rest – Hartford Courant
NFL Draft History: Linebackers and running backs among Bears' best picks — Inside The Hashes
1986 Walter Payton Card 11 and Payton Record Breaker 7 - Hong Kong
Walter Payton - Wikipedia
Gale Sayers' greatness as a Bear left us wanting so much more - Chicago Sun-Times
Gale Sayers, Walter Payton named among best backs in NFL history
Gale Sayers, Bears Hall of Fame running back, dies at 77
Chicago Bears - Wikipedia
Arkush: Your Gale Sayers questions answered