@misc{indiciaef3a939f62e0b,
  title = {Changes in drilling density and discovery rates through time},
  author = {D.R. Collins},
  year = {1985},
  doi = {10.1007/bf01032928},
  url = {https://pubs.usgs.gov/publication/70012892},
  note = {Source identifier: 70012892}
}