@misc{indiciaee485d6de6a07,
  title = {Origins of a national seismic system in the United States},
  author = {John R. Filson and Walter J. Arabasz},
  year = {2016},
  doi = {10.1785/0220160039},
  url = {https://pubs.usgs.gov/publication/70194182},
  note = {Source identifier: 70194182}
}