Gellert, R. Cosmochemistry, Max Planck Institute for Chemistry, Max Planck Society;
Wang, A., Haskin, L. A., Squyres, S. W., Jolliff, B. L., Crumpler, L., Gellert, R., et al. (2006). Sulfate deposition in subsurface regolith in Gusev crater, Mars. Journal of Geophysical Research-Planets, 111(E2): E02S17. doi:10.1029/2005JE002513.