@misc{indiciae339d4d175ec2,
  title = {Contributions to economic geology, 1906: Part II - coal, lignite, and peat},
  author = {Marius Robinson Campbell},
  year = {1907},
  doi = {10.3133/b316},
  url = {https://pubs.usgs.gov/publication/b316},
  note = {Source identifier: b316}
}