Ref Centre -
Online referee assignment, scheduling and management software for sports districts, leagues, clubs and tournaments.
http://www.refcentre.com/

Refshop.com -
Offering referee apparel from brand name manufacturers for baseball, American football, ice hockey, lacrosse and wrestling.
http://www.refshop.com

Refwear -
Offering apparel and supplies for soccer referees in the United States.
http://refwear.com/

Reliable Racing Supply -
 Timing equipment for sporting and competitive events such as software, photocells, printers, message displays, stopwatches and start clocks.
http://www.reliabletiming.com/

RidgeStar Referees -
 Provides overview information and a demonstration of a web based Soccer Referee Management system useful for referee scheduling.
http://www.referees.biz/

Rulesguide.com -
 Easy to follow guide books to help understand the rules of the game. Guide books for many sports including Tennis, Golf, Ice Hockey and basketball.
http://www.rulesguide.com

Score-Clocks Inc. -
 Rent and sell portable, multi-side sports and wrestling specific scoreboards.
http://www.score-clocks.com/

Smitteez -
Offers equipment and apparel for umpires, referees and sports officials in American Football, Soccer and Basketball.
http://www.smitteez.com/