The fragmentation of the copper supply chain 
http://larivelazione.altervista.org/member.php?1414330-MiguelPag 
 
Five Applications for Copper Alloy Wire 
http://forum.dipti.com.bd/index.php?topic=341.0 
 
 
History of Ancient Copper Smelting Pollution During Roman and Medieval Times Recorded in Greenland Ice 
http://madisoncountymo.com/forum/viewtopic.php?f=3&t=19909 
 
Copper Stocks and Flows 
http://jp.yqlog.com/viewthread.php?tid=155091&page=1&authorid=50635 
 
Why Copper Is Used to Make Electrical Wires 
http://jkm666.com/forum.php?mod=viewthread&tid=2961455&extra= 
 
Physical Properties of Copper 
http://ringer.icu/index.php?topic=388.0