@misc{indiciaebf554aeb0c2b,
  title = {Separation and preconcentration of the rare-earth elements and yttrium from geological materials by ion-exchange and sequential acid elution},
  author = {J.G. Crock and F.E. Lichte and G. O. Riddle and C.L. Beech},
  year = {1986},
  doi = {10.1016/0039-9140(86)80137-0},
  url = {https://pubs.usgs.gov/publication/70015618},
  note = {Source identifier: 70015618}
}