@misc{indiciaef5f7463f51b2,
  title = {Preliminary determination of epicenters; monthly listing, April-June 1991},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey},
  year = {1991},
  doi = {10.3133/ofr91600b},
  url = {https://pubs.usgs.gov/publication/ofr91600B},
  note = {Source identifier: ofr91600B}
}