@misc{indiciaec8fc0e523c21,
  title = {Radar attenuation tomography using the centroid frequency downshift method},
  author = {L. Liu and J. W. Lane and Y. Quan},
  year = {1998},
  doi = {10.1016/s0926-9851(98)00024-x},
  url = {https://pubs.usgs.gov/publication/70020291},
  note = {Source identifier: 70020291}
}