Reference

ALLSTAR Network - Aeronautics Learning Laboratory for Science, Technology, and Research
Canadian Advanced Soaring (CAS) - Information about Cross-country Soaring
F.A.A. - Aeronautical Information Manual (AIM) - U.S.A.
F.A.A. Airworthiness Certification of Aircraft and Related Products - U.S.A.
F.A.A. - Air Traffic Publications Library - U.S.A.
F.A.A. - FARs (Federal Aviation Regulations) - U.S.A.
F.A.A. - Pilot/Controller Glossary - U.S.A.
Soaring Wiki - www.gliderpilot.org