1. Allen, T. F. H., and T. B. Starr. 1982. Hierarchy: Perspectives for Ecological Complexity. University of Chicago Press, Chicago.
2. Allen, T. F. H., R. V. O’Neill, and T. W. Hoekstra. 1984. Interlevel relations in ecological research and management: some working principles from hierarchy theory. USDA Forest Service General Tech Report RM-110, Rocky Mountain Forest and Range Experiment Station.
3. Bierkens, M. F. P., P. A. Finke, and P. de Willigen. 2000. Upscaling and Downscaling Methods for Environmental Research. Kluwer Academic Publishers, Dordrecht.
4. Blöschl, G., and M. Sivapalan. 1995. Scale issues in hydrological modelling: a review. Hydrological Processes 9:251-290.
5. Brown, J. H., and G. B. West, editors. 2000. Scaling in Biology. Oxford University Press, New York.