Smucker, Glenn R.; White, T. Anderson; Bannister, Michael(CGIAR System-Wide Program on Property Rights and Collective Action, International Food Policy Research Institute, Washington, DC, 2000)
Hoffmann, Volker; Lamers, John; Kidd, Andrew(Overseas Development Institute, London, Agricultural Research and Extension Network (AGREN), London, 2000)
Fronzaglia, Thomaz; Guedes, Vicente Galileu Ferreira; Santos, Ercilio(V Encuentro de Investigadores Latinoamericanos de Cooperativismo, São Paulo, Brazil, 2008)
Chapman, Robert; Blench, Roger; Kranjac-Berisavljevic, Gordana; Zakariah, A. B. T.(Overseas Development Institute, London, Agricultural Research and Extension Network (AgREN), London, 2003)