@misc{indiciaea216d5e977fe,
  title = {Spectral structure in the Earth's microseismic background between 20 and 40 seconds},
  author = {L.G. Holcomb},
  year = {1998},
  doi = {10.1785/bssa0880030744},
  url = {https://pubs.usgs.gov/publication/70020445},
  note = {Source identifier: 70020445}
}