@misc{indiciae7ef7a87d42df,
  title = {Geochemical survey of the western coal regions; first annual progress report, July 1974},
  author = {Jon J. Connor and Ronald R. Tidball and James A. Erdman and Richard J. Ebens and John R. Keith and Barbara M. Anderson},
  year = {1974},
  doi = {10.3133/ofr74250},
  url = {https://pubs.usgs.gov/publication/ofr74250},
  note = {Source identifier: ofr74250}
}