Evolution of the NFL Rules
Panthers confident Miles Sanders brings value to offense
Chargers' Cameron Dicker 'the right guy' for kicking duties this season – Orange County Register
NFL declares longer extra point experiment a success by making rule permanent
Why the new extra-point rule is changing the NFL – for everyone, NFL
Inbox: You always need 'em in this league
NFL Week 1 Predictions: Our Picks Against the Spread - The New York Times
The NFL made extra points more difficult, but not by much
United States Football League - Wikipedia
Roger Goodell thinks that the extra point after touchdown is almost automatic, we have some ideas