Birch, Brakke, Lofstrom, Pearson
AAS-launchloop-1981-novX.pdf
AIAA-launchloop-1985.pdf
Analog1983.pdf
ISEC-Keithl-Launchloop-2009.pdf
JBIS-Birch-Rings1-1982.pdf
JBIS-Birch-Rings2-1983.pdf
L5News-Brakke-Skyrail-1982.pdf
L5News-Keithl-Launchloop-1982.pdf
SpaceElevatorHistory.pdf