@article{lutter2016a,
  title = {A review and comparative assessment of existing approaches to calculate material footprints}
  author = {Lutter, Stephan; Giljum, Stefan; Bruckner, Martin},
  journal = {Ecological Economics},
  url = {http://www.sciencedirect.com/science/article/pii/S0921800916303299},
  doi = {10.1016/j.ecolecon.2016.03.012},
  year = {2016}
}