@article{dittrich2012the,
  title = {The physical dimension of international trade, part 2: Indirect global resource flows between 1962 and 2005}
  author = {Dittrich, Monika and Bringezu, Stefan and Schütz, Helmut},
  journal = {Ecological Economics},
  doi = {10.1016/j.ecolecon.2012.04.014},
  year = {2012}
}