@misc{indiciaee5796249cc0e,
  title = {Upper mantle electrical conductivity for seven subcontinental regions of the Earth},
  author = {W.H. Campbell and E.R. Schiffmacher},
  year = {1988},
  doi = {10.5636/jgg.40.1387},
  url = {https://pubs.usgs.gov/publication/70013226},
  note = {Source identifier: 70013226}
}