Proceedings of the United Nations interregional Seminar on are concentration in water-short areas : United Nations. New York, USA 14-25 Feb. 1966 / United Nations. Technical Assistance Administration. United Nations. Economic Commission for Asia and the Far East Ore dressing. 624.75 UNP New York : United Nations, 1968. 1968. 1968 Text iii, 342 p. ; eng