1. Airship Technology;Khoury,1999
2. Lieutenant colonel Ryan DE, Jr. Eye in the sky: airship surveillance. In: The airship's potential for intertheater and intratheater airlift. Thesis of School of Advanced Airpower Studies, Air University, Maxwell Air Force Base, Alabama, 1992.
3. Rumerman J. The era of the dirigible. US Centennial of Flight Commission 〈http://www.centennialofflight.gov/essay/Lighter_than_air/dirigibles/LTA9.htm〉.
4. Goodyear Aerospace Corp., Contract NAS2-8643, 1975.
5. Lighter than air: an illustrated history of the development of hot-air balloons and airships;Owen,1999