Goddard Space Flight Center. New Map Provides More Evidence Mars Once Like Earth [online]. [Cit. 2007-08-30]. Dostupné online. Archivované 2012-09-14 z originálu.
harvard.edu
adsabs.harvard.edu
The Tempe volcanic province of Mars and comparisons with the Snake River Plains of Idaho [online]. [Cit. 2007-08-25]. Dostupné online.
Goddard Space Flight Center. New Map Provides More Evidence Mars Once Like Earth [online]. [Cit. 2007-08-30]. Dostupné online. Archivované 2012-09-14 z originálu.