Kieft, T. L., McCuddy, S. M., Onstott, T. C., Davidson, M., Lin, L., Mislowack, B., Pratt, L., Boice, E., Sherwood Lollar, B., Lippmann-Pipke, J., Pfiffner, S. M., Phelps, T. J., Gihring, T., Moser, D. P., van Heerden, A. (2005). Geochemically generated, energy-rich substrates and indigenous microorganisms in deep, ancient groundwater, Geomicrobiol. J., 22 (6), 325-335