@misc{indiciaeefe190f74e1a,
  title = {The evaluation of VLF guided waves as possible earthquake precursors},
  author = {A.J. Michael},
  year = {1996},
  doi = {10.3133/ofr9667},
  url = {https://pubs.usgs.gov/publication/ofr9667},
  note = {Source identifier: ofr9667}
}