Poole, Peter. (1989) 1989. Developing a Partnership of Indigenous Peoples, Conservationists, and Land Use Planners in Latin America. Policy, Planning, and Research Working Papers -- Environment (WPS 245). Washington, DC: Latin America and the Caribbean Technical Dept., World Bank. http://www.worldcat.org/oclc/29810664.
usufruct rights
Barrow, Edmund G. C. (1990) 1990. “Usufruct Rights to Trees: The Role of Ekwar in Dryland Central Turkana, Kenya”. Human Ecology 18 (2): 163-76. http://www.jstor.org/stable/4602963.