1. Amundson, A.: The Carbon budget in soils, Annu. Rev. Earth Planet. Sc., 29, 535–62, 2001.
2. Arnalds, O. and Gretarsson, E.: Generalized Soil Map of Iceland, 2nd Edn., Agric. Res. Inst., Reykjavik, Iceland, 2001.
3. Arinushkina, E. V.: Manual for Chemical Analysis of Soils, 2nd Edn., Moscow State University, Moscow, 487 pp., 1970 (in Russian).
4. Bouma, J. and Van Lanen, H. A. J.: Transfer functions and threshold values: from soil characteristics to land qualities, in: Quantified Land Evaluation, edited by: Beek, K. J., Burrough, P. A., and McCormack, D. E., ITC Publication 6, International Institute for Aerospace Survey and Earth Sciences, Enschede, 106–110, 1987.
5. Batjes, N. H.: Total carbon and nitrogen in the soils of the world, Eur. J. Soil Sci., 47, 151–163, 1996.