@misc{indiciae796e6ffa1ad9,
  title = {Geochemical studies of North American soils: results from the pilot study phase of the North American Soil Geochemical Landscapes Project},
  author = {David B. Smith},
  year = {2009},
  doi = {10.1016/j.apgeochem.2009.04.006},
  url = {https://pubs.usgs.gov/publication/70140566},
  note = {Source identifier: 70140566}
}