1. Blanc-Pamard, C. and Peltre, P. 1984: Dynamique des paysages préforestiers et pratiques culturales en Afrique de l'Ouest (Côte d'lvoire Centrale). Le Développement Rural en Questions Mémoires ORSTOM 106, 55-74.
2. Brochert, J.R. 1968: Geography and systems theory. In Cohen, S.B., editor, Geography and the American environment , Washington: US Information Service , 28, 285-93.
3. Bradley, P. 1983: Underdevelopment and physical geography: bias and relevance in the Sahel. In London Group of the Union of Socialist Geographers, editors, Society and nature: socialist perspectives on the relationship between human and physical geography, London: the Group, 32-46.