Here are my suggestions:
Daniel, C.J. and L. Frid (in press). Predicting landscape vegetation dynamics using state-and-transition simulation models. In: Kerns, B.K., A. Shlisky, and C.J. Daniel (eds.) 2012. Proceedings of the First Landscape State-and-Transition Simulation Modeling Conference, June 14-16, 2011, Portland, Oregon. Gen. Tech. Rep. PNW-869, Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station.
Apex Resource Management Solutions Ltd. (2012). Path Landscape Model. Retrieved from http://www.apexrms.com/path