@misc{indiciaef5342fbd1180,
  title = {The urban environmental gradient: Anthropogenic influences on the spatial and temporal distributions of lead and zinc in sediments},
  author = {Edward Callender and Karen C. Rice},
  year = {1999},
  doi = {10.1021/es990380s},
  url = {https://pubs.usgs.gov/publication/70022510},
  note = {Source identifier: 70022510}
}