United States Ultralight Organization: https://www.usua.org/index.html
FAR Part 103: https://www.usua.org/Rules/faa103.htm
The Experimental Aircraft Association: https://www.eaa.org/eaa
Home Built Airplanes: http://www.homebuiltairplanes.com
Aircraft Spruce & Specialty Company: https://www.aircraftspruce.com
Air Tech Inc: https://air-techinc.com
North Wing Sports: https://northwingsports.com/collections/ultralight-homebuilder-parts
Ultralight Aircraft Parts: https://sites.google.com/site/ultralightaircraft/