1. Alexander M 1977 Introduction to Soil Microbiology. 2nd ed. John Wiley and Sons, New York, NY.
2. Altieri M A 1991 How best can we use biodiversity in agroecosystems? Outlook Agric. 20, 15–23.
3. Arshad M A and Coen G M 1992 Characterization of soil quality: physical and chemical criteria. Am. J. Alternative Agric. 7, 25–31.
4. Atlas R M 1984 Use of microbial diversity measurements to assess environmental stress.In Current Perspectives in Microbial Ecology. Eds. M J Klug and C A Reddy. pp 540–545 American Society for Microbiology, Washington DC.
5. Barbault R and Hochberg M E 1992 Population and community level approaches to studying biodiversity in international research programs. Acta Ecol. 13, 137–146.