@misc{indiciae556eaaa7993c,
  title = {Time-dependent spectral analysis of thirty-one strong-motion earthquake records},
  author = {Virgilio Perez},
  year = {1974},
  doi = {10.3133/ofr7448},
  url = {https://pubs.usgs.gov/publication/ofr7448},
  note = {Source identifier: ofr7448}
}