@misc{indiciaee5eb1d601ded,
  title = {Contributions to economic geology, 1907: Part II - coal and lignite},
  author = {Marius Robinson Campbell},
  year = {1909},
  doi = {10.3133/b341},
  url = {https://pubs.usgs.gov/publication/b341},
  note = {Source identifier: b341}
}