Boeing Bird of Prey - Information on the aircraft, which has made numerous flights since being secretly launched in 1996. - http://www.air-attack.com/page.php?pid=1
The Society of Experimental Test Pilots - An international organization that seeks to promote air safety and contributes to aeronautical advancement. Provides information on programs, activities and membership. - http://www.setp.org
Experimental and Research Aircraft - Gallery featuring history, specifications, schematics, pictures, and data on several historic planes. - http://www.aerospaceweb.org/aircraft/research/
The X-Planes Data Site - X stands for eXperimental, and experimentation is the single purpose of the X-planes. - http://users.dbscorp.net/jmustain/xpmain.htm
UFOSeek: Military Aircraft - Links to sites on mystery military aircraft like the Aurora. - http://www.ufoseek.com/Military_Aircraft/index.html
FAS Mystery Aircraft - Information on the mystery aircraft of the U.S. military like the Aurora. - http://www.fas.org/irp/mystery/index.html