This long and comprehensive article deals mostly with finding the type and quality of primary doctor you need but also has tips on emergecy care and referrals. (Choosing a Doctor. Your Guide to Choosing Quality Health Care. AHCPR
Pub. No. 99-0012, December 1998. Agency for Health Care Policy and Research)
Do you need to find a pain specialist or pain clinic in your area? On this page just choose your state, province, or country and click "begin search."
The Dannemiller Foundation lists hundreds of pain specialists and pain clinics worldwide. The complete mailing address of each is included for your convenience.
Also, this newly-revised site offers many articles about pain - some dealing with cluster headache.