1. The nature of predation: prey dependent, ratio dependent, or neither;Abrams;TREE,2000
2. Ecology: Individuals, Populations and Communities;Begon,1990
3. A Primer on Non-Market Valuation,2003
4. A comparison of direct observations and collections of prey remains in determining the diet of golden eagles;Collopy;Journal of Wildlife Management,1983
5. Valuing ecosystem services: philosophical bases and empirical methods;Goulder,1997