Squyres, S. W., Arvidson, R. E., Bollen, D., Bell, J. F., Bruckner, J., Cabrol, N. A., et al. (2006). Overview of the Opportunity Mars Exploration Rover mission to Meridiani Planum: Eagle crater to Purgatory ripple. Journal Geophysical Research, 111(E12): E12S12. doi:10.1029/2005JE002495.