Mark Wade's fantastic "Encyclopedia Astronautica"
"Part-time-models": Real 3d-physical-like spacecraft models!
Alexander Chernov's VRML Soviet/Russian spacecraft models
Monster list of every space model ever
Mr. Charles P. Vick's FAS drawings
Favorite related publications
At the Edge of Space: The X-15 Flight Program
Milton O. Thompson,
Smithsonian Institution Press; 1992
Dream Machines: A Pictorial History of the Spaceship...
Kreiger Publishing; 1993
Yeager: A Biography
Gen. Chuck Yeager and Leo Janos,
Bantam Books; 1985
Illustrated Encyclopedia of Space Technology
Orion Books; 1989
Rendezvous in Space
E.P. Dutton & Co.; 1962
Quest, The History of Spaceflight Quarterly
"Soyuz-based Manned Reconnaissance Spacecraft"
Vol. 6, No. 1, Spring 1998
Roy Houchin, for providing access to his unbelievable collection of Dyna Soar material.
Mark Wade, for his enthusiastic response to the first images I showed him.