Lal, R. , Soil Quality and Agricultural Sustainability, Ann Arbor Press., 1998
Sullivan, P., El Manejo Sostenible de Suelos, NCAT , 2007
Magdoff, F., Weil, R.R., Soil organic matter in sustainable agriculture, CRC Press. London, 2004
Raman, S., Agricultural Sustainability: Principles, processes and prospects, New York : Food Products Press, 2006