@misc{indiciae72e66659337a,
  title = {Geology and mineral resources of Paraguay--a reconnaissance, with sections on Igneous and metamorphic rocks and soils},
  author = {E.B. Eckel and Charles Milton and P.T. Sulsona},
  year = {1959},
  doi = {10.3133/pp327},
  url = {https://pubs.usgs.gov/publication/pp327},
  note = {Source identifier: pp327}
}