1. Alexander, E.B., Kissinger, E., Huecker, R.H., Cullen, P., 1989. Soils of southeast Alaska as sinks for organic carbon from atmospheric carbon dioxide. In: Proceedings of the Conference on the Stewardship of Soil, Air, and Water Resources. USDA Forest Service, Juneau, AK.
2. The carbon content of topsoil and its geographical distribution in France;Arrouays;Soil Use Manage.,2001
3. Aslyng, H.C., 1978. Miljø og jordbrug. DSR, Copenhagen.
4. Total carbon and nitrogen in the soils of the world;Batjes;Eur. J. Soil Sci.,1996
5. Batjes, N.H., 1999. Management options for reducing CO2-concentrations in the atmosphere by increasing carbon sequestration in the soil. Report 410-200-031. Dutch National Research Programme on Global Air Pollution and Climate Change. ISRIC Technical Paper 30, Wageningen, The Netherlands.