@misc{indiciae6083ec13e0ae,
  title = {United States earthquakes, 1968},
  author = {J.L. Coffman and W.K. Cloud},
  year = {1984},
  doi = {10.3133/ofr84968},
  url = {https://pubs.usgs.gov/publication/ofr84968},
  note = {Source identifier: ofr84968}
}