1. Rohde, H. Science 248, 1217–1219 (1990).
2. IPCC in Climate Change: The IPCC Scientific Assessment, (eds Hoghton J. T., Jenkins C. J. & Ephraums J. J.) Introduction, 36–37, (Cambridge Univ. Press, Cambridge, (1990).
3. Barry, R. G. in Encyclopedia of Earth System Science vol. 1, 517–524 (Academic, San Diego. 1992).
4. Bouwman, A. F. in Soils and the Greenhouse Effect (Wiley, Chichester, 1990).
5. Steudler, P. A., Bowden, R. D., Melillo, J. M. & Aber, J. D. Nature 341, 314–316 (1989).