@misc{indiciaeccb0b591dc3f,
  title = {Impervious surface area in the Upper White Rock Creek watershed},
  author = {R.H. Ollman},
  year = {1969},
  doi = {10.3133/ofr69187},
  url = {https://pubs.usgs.gov/publication/ofr69187},
  note = {Source identifier: ofr69187}
}