@misc{indiciaea18f20cd9734,
  title = {Chemical analyses of coal from the Healy, Kenai, Seldovia, and Utokok River 1:250,000 quadrangles, Alaska},
  author = {Ronald H. Affolter and Frederick Otto Simon and Gary D. Stricker},
  year = {1981},
  doi = {10.3133/ofr81654},
  url = {https://pubs.usgs.gov/publication/ofr81654},
  note = {Source identifier: ofr81654}
}