1. Charlson, R. J., Langner, J. & Rodhe, H. Tellus A/B 43, 152–163 (1991).
2. Twomey, S. Atmospheric Aerosols (Elsevier, Amsterdam, 1977).
3. Charlson, R. J., Lovelock, J. E., Andreae, M. O. & Warren, S. G. Nature 326, 655–661 (1987).
4. Wigley, T. M. L. Nature 339, 365–367 (1989).
5. Zimmermann, P. H. in Proc. 16th NATO/CCMS int. Tech. Mtg Air Pollution Modeling and its Application, 593–608 (Reidel, Dordrecht, 1987).