@misc{indiciaeb172cd9d0af2,
  title = {Digital Raster Graphics},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey},
  year = {1997},
  doi = {10.3133/fs12295},
  url = {https://pubs.usgs.gov/publication/fs12295},
  note = {Source identifier: fs12295}
}