1. Mars helicopter technology demonstrator. 2018 AIAA atmospheric flight mechanics conference, 8-12 January 2018, Kissimmee, Florida;Balaram,2018
2. Glacieres or Freezing Caverns. Allen, Lane & Scott, Philadelphia, 337pp;Balch,1900
3. Nature, occurrence, and origin of dry permafrost;Bockheim,1998
4. Cave biosignature suites: microbes, minerals and Mars;Boston;Astrobiology,2001
5. Some martian volcanic features as viewed from the Viking orbiters;Carr;J. Geophys. Res.,1977