1) AGREN G. I. Theoretical Ecosystem Ecology.. Cambridge University Press. (1996)
2) AGREN G. I. Ecosystem physiology-soil organic matter. Global Change : Effects on Coniferous Forests and Grasslands. John Wiley & Sons. (1996) p.207-228.
3) AJTAY G. L. Terrestrial primary production and phytomass. The Global Carbon Cycle. John Wiley & Sons. (1979) p.129-181.
4) ANDERSON J. M. Responses of soils to climate change. Advances in Ecological Research. (1992) vol.22, p.163-210.
5) ARNOLD R. W. Role of soil survey in obtaining a global carbon budget. Soils and Global Change. CRC Lewis. (1995) p.257-263.