1. Access Science Browse Encyclopedia, 2001. Engineering & Materials, Mining Engineering, McGraw-Hill, New York. Accessed in September 2001.
2. Bertram, B., 2000. Sodium chloride, economic aspects. Kirk-Othmer Encyclopedia of Chemical Technology, Wiley & Sons, New York. Available from: http://www.mrw.interscience.wiley.com. Accessed in February 2002.
3. Borg, G., Steen, B., 2001. Availability of metals in the earth's crust – Leaching tests on silicate minerals. CPM Report 2001:12, Chalmers University of Technology, Göteborg, Sweden, 2001.
4. Boustedt, I., 1994. Eco-profiles of the European plastics industry. Report 7, PVCD, Association of Plastics Manufacturers in Europe, Brussels, Belgium, December 1994.
5. Environment Australia, 1999. Emission estimation technique manual for explosives detonation and firing ranges. National Pollutant Inventory, Environment Australia, March 1999.