Petschel-Held, G., Block, A., Cassel-Gintz, M., Kropp, J. P., Lüdecke, M. K. B., Moldenhauer, O., Reußwig, F., Schellnhuber, H. J. (1999): Syndromes of global change: a qualitative modelling approach to assist global environmental management. - Environmental Modeling and Assessment, 4, 4, 295-314.https://doi.org/10.1023/A:1019089704864