Li, W., Packard, N., & Langton, C. (1990). Transition Phenomena in Cellular Automata Rule Space. Physica D (45), 77-94.
Colasanti, R. L., R. Hunt, and L. Watrud. “A simple cellular automaton model for high-level vegetation dynamics.” Ecological Modelling 203.3 (2007): 363-374.