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  1. ^ French, Lloyd (18–22 June 2001). "Cryobots: An Answer to Subsurface Mobility in Planetary Icy Environments" (PDF). Proceeding of the 6th International Symposium on Artificial Intelligence and Robotics & Automation in Space. Retrieved 20 April 2016.{{cite journal}}: CS1 maint: date format (link)
  2. ^ Zimmerman, W.; Bonitz, R.; Feldman, J. (2001-01-01). "Cryobot: an ice penetrating robotic vehicle for Mars and Europa". Aerospace Conference, 2001, IEEE Proceedings. 1: 1/311–1/323 vol.1. doi:10.1109/AERO.2001.931722.