@misc{indiciaed646b5d7f5cc,
  title = {Geographic information system analysis of topographic change in Philadelphia, Pennsylvania, during the last century},
  author = {P. G. Chirico and J. B. Epstein},
  year = {2000},
  doi = {10.3133/ofr00224},
  url = {https://pubs.usgs.gov/publication/ofr00224},
  note = {Source identifier: ofr00224}
}