@misc{indiciaef02d531af524,
  title = {Computer studies of the composition of Chilean nitrate ores: Data reduction, basic statistics and correlation analysis},
  author = {Bernardo F. Grossling and George Edward Ericksen},
  year = {1971},
  doi = {10.3133/ofr71138},
  url = {https://pubs.usgs.gov/publication/ofr71138},
  note = {Source identifier: ofr71138}
}