1. Ad Astra 2011, see 〈www.adastrarocket.com/aarc/AboutUs〉.
2. M. Augelli, G. Bignami, C. Bruno, E. Calligarich, E. De Maria, G. Mulas, M. Musso, A. Pellizzoni, W. Piperno, R. Piva, B. Procacci, M. Rosa-Clot, C. Rubbia, Report of the Working Group on a Preliminary Assessment of a New Fission Fragment Heated Propulsion Concept and its Applicability to Manned Missions to the Planet Mars (Project 242), ASI Internal Report, Rome, March 15, 1999 (proprietary).
3. S.K. Borowski, L.A. Dudzinski, M.L. McGuire, Artificial Gravity Human Exploration Missions to Mars and Near Earth Asteroids Using ‘Bimodal’ NTR Propulsion, Paper AIAA 2000-3115, presented at the 36th AIAA/ASME/SAE/ASEE Joint Propulsion Meeting, 16–19 July 2000, Huntsville, AL, 2000
4. M. Coletti, S.B. Gabriel, Design of a dual stage ion engine for the Hiper project, Paper presented at the AIAA/ASME/SAE/ASEE 46th Joint Propulsion Conference, Nashville, 25–28 July 2010.
5. Future Space Propulsion and Power;Czysz,2009