@misc{indiciae9a3ab5e39621,
  title = {Real time monitoring of radon as an earthquake precursor in Iceland},
  author = {Wallace S. Broecker and J.C. Goddard and Egill Hauksson},
  year = {1981},
  doi = {10.3133/ofr81877},
  url = {https://pubs.usgs.gov/publication/ofr81877},
  note = {Source identifier: ofr81877}
}