1. P. W. Anderson. More is different – broken symmetry and the nature of the hierarchical structure of science. Science, 177(4047):393–396, 1972.
2. G. L. Gómez. Dynamic Probabilistic Models and Social Structure – Essays on Socioeconomic Continuity. Springer Netherlands, Dordrecht, 1992.
3. G. Haag. A stochastic theory on sudden urban growth. In Konzepte SFB 230, Heft 25, pages 255–271. SFB 230 (Natürliche Konstruktionen/Natural Structures), Stuttgart, 1986.
4. G. Haag. Dynamic Decision Theory – Applications to Urban and Regional Topics. Kluwer Academic Publishers, Dordrecht, 1989.
5. G. J. Papageorgiou. On sudden urban growth. Environment and Planning A: Economy and Space, 12(9):1035–1050, 1980.