Scientific positions to meet the challenge of rural and urban poverty in developing countries : proceedings of a conference organized by the German Foundation for International Development and the Centre for Regional Development Research at the Justus-Liebig-University Giessen, June 22-26, 1987 / Andreas Kopp (editor). (Schriften des Zentrums für Regionale Entwicklungsforschung der Justus-Liebig-Universität Gießen, 1987)