@misc{indiciae49907af3b93a,
  title = {Large-scale magnetic field perturbation arising from the 18 May 1980 eruption from Mount St. Helens, Washington},
  author = {R.J. Mueller and M.J.S. Johnston},
  year = {1989},
  doi = {10.1016/0031-9201(89)90209-4},
  url = {https://pubs.usgs.gov/publication/70015443},
  note = {Source identifier: 70015443}
}