More defensive penalties causes change in NFL -- Tuesday Morning Quarterback - ESPN
NFL approves 2 rule changes; postseason OT altered
New NFL overtime rules, explained: How Bills vs. Chiefs helped change playoff OT format
NFL approves 2 rule changes; postseason OT altered
NFL teams submit 2 rule change proposals aimed at tweaking overtime
NFL approves 2 rule changes; postseason OT altered
NFL eliminates preseason OTs, defeats onside kick proposal
Procedures for assigning mixed crews for the NFL playoffs – Football Zebras
Football Zebras - Analysis and commentary of the NFL's officials and the calls they make
American football rules - Wikipedia
Rules proposal scorecard: Which new NFL rules were passed for 2016? – Football Zebras
With Overtime Rules Changed, What Other NFL Rules Should Be Examined Next?, News, Scores, Highlights, Stats, and Rumors
New overtime formats, onside kick alternative among 11 proposed NFL rule changes
NFL approves 2 rule changes; postseason OT altered