@misc{indiciaee578bb184591,
  title = {Statistics of petroleum exploration in the non-Communist world outside the United States and Canada},
  author = {David H. Root and Emil D. Attanasi and Robert M. Turner},
  year = {1987},
  doi = {10.3133/cir981},
  url = {https://pubs.usgs.gov/publication/cir981},
  note = {Source identifier: cir981}
}