Bibliography
Pro Football Stats, History, Scores, Standings, Playoffs, Schedule & Records | Pro-Football-Reference.com
Complete source for pro football history including complete player, team, and league stats, awards, records, leaders, rookies and scores.
A Terrific football, baseball, hockey, basketball reference
Out of print:
"Pro Football **" by Bear Kirow
"Street & Smith's Pro Football Yearbook"
Official NFL team Media Guides
Other sites:
https://sports.yahoo.com/nfl
www.nfl.com