@misc{indiciae02964265edd2,
  title = {Geologic map of the eastern Rub Al Khali quadrangle, Kingdom of Saudi Arabia},
  author = {E.L. Elberg and Ruel D. Gierhart and Leon F. Ramirez},
  year = {1963},
  doi = {10.3133/i215a},
  url = {https://pubs.usgs.gov/publication/i215A},
  note = {Source identifier: i215A}
}