1. Albrecht, W.A., 1938. Loss of soil organic matter and its restoration. In: United States Department of Agriculture, Soils and Men: Yearbook of Agriculture 1938. US Government Printing Office, pp. 347–360.
2. Soil Organic Matter and its Role in Crop Production;Allison,1973
3. The carbon budget in soils;Amundson;Annual Review of Earth and Planetary Sciences,2001
4. Fundamentals of Soil Ecology;Coleman,2004
5. Defining and assessing soil quality;Doran,1994