Чөлөөт нэвтэрхий толь, Википедиагаас
Гадаад холбоос [засварлах]
- National Pollutant Inventory - Copper and compounds fact sheet
- Copper Resource Page. Includes 12 PDF files detailing the material properties of various kinds of copper, as well as various guides and tools for the copper industry.
- The Copper Development Association has an extensive site of properties and uses of copper; it also maintains a web site dedicated to brass, a copper alloy.