@misc{indiciae8821c642ccdb,
  title = {Stripping-coal deposits on lower Lignite Creek, Nenana coal field, Alaska},
  author = {Clyde Wahrhaftig and Joseph H. Birman},
  year = {1954},
  doi = {10.3133/cir310},
  url = {https://pubs.usgs.gov/publication/cir310},
  note = {Source identifier: cir310}
}