@misc{indiciae2483a7592a6d,
  title = {BOREHOLE NEUTRON ACTIVATION: THE RARE EARTHS.},
  author = {J.L. Mikesell and F. E. Senftle},
  year = {1987},
  doi = {10.1109/23.12664},
  url = {https://pubs.usgs.gov/publication/70014632},
  note = {Source identifier: 70014632}
}