1. Developing sustainable agroecosystems;Altieri;BioScience,1983
2. DRYPLAN: a decision support system for the sustainable management of dry to arid rangelands;Biggins;Agric. Syst. Inf. Technol.,1992
3. Plant-herbivore systems;Caughley,1976
4. Guidelines: Land evaluation for extensive grazing;FAO,1991
5. Simulation of biological systems: some problems and progress;Innis,1972