@misc{indiciaeca494d1af5fd,
  title = {Types of maps},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey},
  year = {1991},
  doi = {10.3133/70039403},
  url = {https://pubs.usgs.gov/publication/70039403},
  note = {Source identifier: 70039403}
}