http://en.wikipedia.org/wiki/Official_(American_football)

http://www.footballofficials.com/

http://football.about.com/cs/football101/a/bl_officials.htm

http://vtfootballofficials.com/index.htm

http://www.nvfoa.com/

http://www.footballofficialscamp.com/

http://www.wdfoa.org/

http://www.fvfo.org/

http://www.naso.org/BeOfficial/sportspages/football.html

http://www.wofoa.org/