American Ambulance Association: http://the-aaa.org

California Ambulance Association: http://www.the-caa.org
Indiana Ambulance Association: http://www.the-iaa.org
Iowa Emergency Medical Services Association: http://www.iemsa.net
Kansas EMT Association: http://www.kemta.com/
Kentucky Ambulance Providers Association: http://www.hultgren.org/assoc/kapa/index.html
Maine Ambulance Association: http://www.the-maa.org
Minnesota Ambulance Association: http://www.mnems.org
Ohio Ambulance and Medical Transportation Association: http://www.oaaonline.org
South Carolina EMS Association: http://www.scemsa.com/
Wisconsin EMS Association: http://www.wemsa.com/
Vermont Ambulance Association: http://www.the-vaa.org/

Illinois Compiled Statutes http://www.ilga.gov/legislation/ilcs/ilcs.asp
IPA Handbook for Providers of Transportation Services  http://www.hfs.illinois.gov/handbooks/chapter200.html

CMS Ambulance Service Providers Home Page http://www.cms.hhs.gov/suppliers/ambulance/