G. Engelen and A. Schutzelaars, Computer Systems that Enhance the Productivity of Public-Sector Planners, International Journal of Public Administration, volume 17, issue 1, p.119-154 R. White and G. Engelen, Cellular Dynamics and GIS: Modelling Spatial Complexity, Geographical Systems, volume 1, p.237-253 R. White and G. Engelen, Urban System Dynamics and Cellular Automata: Fractal Structures Between Order and Chaos, Chaos, Solitons, and Fractals (Special issue), volume 4, p.563-583