@misc{indiciae83fc9512e38b,
  title = {Geologic map of the Yemen Arab Republic (San'a')},
  author = {M. J. Grolier and W.C. Overstreet},
  year = {1978},
  doi = {10.3133/i1143b},
  url = {https://pubs.usgs.gov/publication/i1143B},
  note = {Source identifier: i1143B}
}