1. ICSG(International Copper Study Group) The World Copper Factbook2018.
2. Copper Development Association Copper: Properties and Applications.https://copperalliance.org.uk/knowledge‐base/education/education‐resources/copper‐properties‐applications/(accessed July 26 2019).
3. Copper Development Association Copper Recycling and Sustainability 1.https://copperalliance.org.uk/knowledge‐base/education/education‐resources/copper‐recycling‐sustainability‐1/(accessed July 26 2019).
4. The influence of soil heavy metals pollution on soil microbial biomass, enzyme activity, and community composition near a copper smelter