Chambers, R. (1991) Farmer first: a practical paradigm for the third agriculture. In: M. Altieri and S.B. Hecht (eds.), Agroecology and small farm development. CRC Press, Boca Raton, USA. pp. 237-244.

Doran, J.W. and A.J. Jones (1996) Methods for assessing soil quality. SSSA Special Publication 49, ASA, Madison, USA.

Ortiz, B., C. Fragoso, I. Mboukou, B. Pashanasi, B.K. Senapati and A. Contreras (1999) Perception and use of earthworms in tropical farming systems. In: P. Lavelle, L. Brussaard and P.F. Hendrix (eds.), Earthworm management in tropical agroecosystems. CAB International, Wallingford, U.K. pp. 239-252.

Pankhurst, C.E., B.M. Doube and V.V.S.R. Gupta (1997) Biological indicators of soil health. CAB International, Wallingford, U.K.

Puentes, R. and M.J. Swift (2000) Tropical soil ecology: matching research opportunities with farmers’ needs. In: M.J. Swift (ed.), Managing the soil biota for sustainable agriculture: Opportunities and challenges. TSBF, Nairobi, Kenya.

Swift, M.J. (1997) Biological management of soil fertility as a component of sustainable agriculture: Perspectives and prospects with particular reference to tropical regions. In: L. Brussaard and R. Ferrera-Cerrato (eds.), Soil ecology in sustainable agricultural systems. Lewis Publishers, Boca Raton, USA. pp. 137-159.

Swift, M.J. (1999) Towards the second paradigm: Integrated biological management of soil. In: J.O. Siqueira, F.M.S. Moreira, A.S. Lopes, L.R.G. Guilherme, V. Faquin, A.E. Furtani Neto and J.G. Carvalho (eds.), Inter-relação fertilidade, biologia do solo e nutrição de plantas. UFLA, Lavras, Brasil. pp. 11-24.

TSBF (2000) The biology and fertility of tropical soils. Tropical Soil Biology and Fertility Programme Report 1997-1998. TSBF, Nairobi, Kenya.