NFL considering sky judge, other replay changes as preseason experiments - The Washington Post
How NFL officiating issues drove discussion at Fall League Meeting - Sports Illustrated
Sky Judge' Official Is a No-Brainer for the NFL, News, Scores, Highlights, Stats, and Rumors
NFL Rule Changes: Expanded replay on pass interference key topic - Sports Illustrated
With Overtime Rules Changed, What Other NFL Rules Should Be Examined Next?, News, Scores, Highlights, Stats, and Rumors
Official (gridiron football) - Wikipedia
NFL's instant replay officials have new powers, but owners weren't interested in other major rules changes - The Boston Globe
Saints owner calls for changes in officiating – Football Zebras
NFL Sky Judge: How the New Process Works + Impact on Games