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UNDTCD -New York, NY, US,
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G. J. Heij y Meinardi, C. R.,
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M. Detay, Poyet, P., y Brisson, E.,
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P. Heyns,
«Perspective on water affairs». Namibia, Department of Water Affairs, Investigations and Research, Windhoek, Namibia, p. 63 p.: 5 fig., 5 maps, 27 tab., 1991.
D. M. Nielsen,
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del'Hydrauli Mines,
«Projet hydraulique villageoise et assainissement : quatrieme rapport annuel d'execution». Mali, Ministere des Mines, de l'Hydraulique et de l'Energie, Direction Nationale de l'Hydraulique, Bamako, Mali, p. 30 p. : tab., 1991.
UN Economic Commission for Africa -Addis Ababa, ET, ECA,
«Study on large-scale water transfer in Africa». United Nations Economic Commission for Africa (ECA), Addis Ababa, Ethiopia, p. 39, 24 p.: 3 fig., 4 tab., 1991.
S. S. Luxton, Heineman, M. C., Hodgkin, J. P., Lang, P. T., Meyer, F. W., Miner, R., Schartzman, P. N., y Taylor, K. C.,
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