References
- Astakhov, Denisov, and Pavlov (1994) 'prospecting and exploration in the Soviet Union', In Hans Landsberg, John Tilton and rodderick Eggert, eds. World Mineral Exploration Trends (Washington, DC., Resources for the Future)
- Bejanova, M.P. and H.P. Piskorsky (1989) 'classification of hard economic mineral resources and resources: Principles and special features'. Seminar on Modern Methods of Mineral Prospecting, Tbilisi, Georgia,30 October-10 November 1989, 21p
- United Nations (2000) Atlas of Mineral Resources of the Escap Region, Vol 15, New York, 216p
- United States Bureau fo Mines and United States Geological Survey (1980) 'Principles of a resources/reserve classification for minerals'. USGS Circular 831 (Washington, DC)