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Lua i Stíl Chicago (17ú heag.)Seminar [on] Agricultural Intensification and Environment in Tropical Areas (1990 : Brussels), Academie royale des sciences d'outre-mer, R. Dellere, agus J.-J Symoens. Agricultural Intensification and Environment in Tropical Areas: Seminar, Brussels, 5-6 June 1990. [Wageningen, The Netherlands] : Brussels: Technical Center for Agriculture and Rural Co-operation, Royal Academy of Overseas Sciences, 1991.
Lua MLA (9ú heag.)Seminar [on] Agricultural Intensification and Environment in Tropical Areas (1990 : Brussels), et al. Agricultural Intensification and Environment in Tropical Areas: Seminar, Brussels, 5-6 June 1990. Technical Center for Agriculture and Rural Co-operation, Royal Academy of Overseas Sciences, 1991.