1. Walker, J. C. G., Hays, P. B. & Kasting, J. F. J. geophys. Res. 86, 9776–9782 (1981).
2. Berner, R. A., Lasaga, A. C. & Garrels, R. M. Am. J. Sci. 283, 641–643 (1983).
3. Lasaga, A. C., Berner, R. A. & Garrels, R. M. in The Carbon Cycle and Atmospheric CO2: Natural Variations Archean to Present, Geophys. Monogr. 32, (eds Sundquist, E. T. & Broecker, W. S.) 397–411 (Am. geophys. Un., Washington, 1985).
4. Budyko, M. I., Ronov, A. B. & Yanshin, A. L. History of the Earth's Atmosphere (Springer, Berlin, 1987).
5. Volk, T. Am. J. Sci. 287, 763–779 (1987).