History of American Football: You Can Thank T.R. for the NFL
How NFL Players Have Evolved
Top 10 upsets in NFL history
The Complicated History of the NFL in Los Angeles
Vikings Beat Colts for Biggest Comeback in NFL History - The New
NFL Record: What is the record for the longest game in NFL history
NFL milestones by Black players and coaches - Los Angeles Times
The History of Professional Football in America
History of the NFL football helmet
UI Press, Richard C. Crepeau