- Author: Robert A. Freitas Jr.
- Language: English
- Year: 2022
- Author: Robert A. Freitas Jr.
- Language: English
- Year: 1979
- Author: Robert A. Freitas Jr. Ralph C. Merkle
- Language: English
- Year: 2004
- Author: Robert A. Freitas Jr.
- Language: English
- Year: 2003
- Author: Robert A. Freitas Jr. Ralph C. Merkle
- Language: English
- Year: 2004