@misc{indiciae838dfdbe88f7,
  title = {United States National seismograph network},
  author = {Robert P. Masse and J.R. Filson and A. Murphy},
  year = {1989},
  doi = {10.1016/0040-1951(89)90063-2},
  url = {https://pubs.usgs.gov/publication/70015357},
  note = {Source identifier: 70015357}
}