1. Food security and nutrition monitoring — a conceptual framework, issues, and challenges;Babu;Food Policy,1994
2. Babu, S.C., 1997. Natural Resource and Sustainability Monitoring. A conceptual framework, issues, and challenges. Outreach Division Discussion Paper No. 17, International Food Policy Research Institute, Washington, DC.
3. Becker, B., 1997. Sustainability assessment: a review of values, concepts, methodological approaches. Issues in Agriculture 10. Consultative Group on International Agricultural Research, CGIAR Secretariat, The World Bank, Washington, DC.
4. Bie, S.W., 1990. Dryland Degradation Measurement Techniques. Environment Working Paper No. 26, The World Bank, Washington, DC.
5. Long-term ecological research;Callahan;BioScience,1984