1. Bremen, H., Kessler, J.-J., 1995. Woody Plants in Agro-ecosystems of Semi-arid Regions. Springer, Berlin, 340 pp.
2. Resource limitations in the Sahelian agriculture;Bremen;Global Environ. Change,2001
3. Bumigeb, 1998. Geological Maps of Yatenga Region, Burkina Faso. Bumigeb, Ouagadougou.
4. CPCS, 1967. Commission de Pédologie et de Cartographie des Sols, Classification des Sols. Rapport ENSA Grignon, 87 pp.
5. FAO, 1987. Consultations on Irrigation in Africa. FAO Irrigation and Drainage, Paper No. 42. FAO, Rome.