* "Mining the Sky: Untold Riches from the Asteroids, Comets, and Planets" / John S. Lewis (1998) ISBN 0-201-47959-1* Ricky Lee: Law and Regulation of Commercial Mining of Minerals in Outer Space.
* "Mining the Sky: Untold Riches from the Asteroids, Comets, and Planets" / John S. Lewis (1998) ISBN 0-201-47959-1* The Technical and Economic Feasibility of Mining the Near-Earth Asteroids, M. J. Sonter.