@misc{indiciaebaf858c261d9,
  title = {Trends in Engineering Geologic and Related Mapping 1972–1983},
  author = {David J. Varnes and Jeffrey R. Keaton},
  year = {1983},
  doi = {10.2113/gseegeosci.xxi.3.255},
  url = {https://pubs.usgs.gov/publication/70011178},
  note = {Source identifier: 70011178}
}