@misc{indiciae75a6acc86131,
  title = {Tilt precursors before earthquakes on the San Andreas fault, California},
  author = {M.J.S. Johnston and C.E. Mortensen},
  year = {1974},
  doi = {10.1126/science.186.4168.1031},
  url = {https://pubs.usgs.gov/publication/70011055},
  note = {Source identifier: 70011055}
}