@misc{indiciae057289308de7,
  title = {Free-iron and -manganese oxide content of reference clays},
  author = {B. J. Anderson and E. A. Jenne},
  year = {1970},
  doi = {10.1097/00010694-197003000-00004},
  url = {https://pubs.usgs.gov/publication/70226768},
  note = {Source identifier: 70226768}
}