@misc{indiciae200b4961f59c,
  title = {Major- and Trace-Element Concentrations in Soils from Two Geochemical Surveys (1972 and 2005) of the Denver, Colorado, Metropolitan Area},
  author = {James E. Kilburn and David B. Smith and L. Graham Closs and Steven M. Smith},
  year = {2007},
  doi = {10.3133/ds299},
  url = {https://pubs.usgs.gov/publication/ds299},
  note = {Source identifier: ds299}
}