7Persson T, Lundkvist H, Wiren A, et al. 1989. Effects of acidification and liming on carbon and nitrogen mineralization and soil organisms in mor humus. Water, Air and Soil Pollu, 45(1/2):77-96.
8Paustian K,Andren O,Janzen H. 1997. Agricultural soil as a C sink to offset CO2 emissions. Soil Use Manage, 13:230- 244.
9Schlesinger W H. 1984. Soil organic matter: a source of atmospheric CO2//Woodwell G M. The Role of Terrestrial Vegetation on the Global Carbon Cycle. New York: John Wiley.
