@article{billen2009the,
  title = {The food-print of Paris: long-term reconstruction of the nitrogen flows imported into the city from its rural hinterland}
  author = {Billen, Giles, and Barles, Sabine, and Garnier, Josette, and Rouillard, Josephine, and Benoit, Paul},
  journal = {Regional Environmental Change},
  doi = {10.1007/s10113-008-0051-y},
  year = {2009}
}