@article{d2007spatial,
  title = {Spatial characterisation of multi-level in-use copper and zinc stocks in Australia}
  author = {D. van Beers and Thomas E. Graedel},
  journal = {Journal of Cleaner Production},
  doi = {doi:10.1016/j.jclepro.2006.06.022},
  year = {2007}
}