@misc{indiciae58600c88777d,
  title = {Preliminary geologic map and lignite deposits of the Strasburg NW Quadrangle, Arapahoe and Adams counties, Colorado},
  author = {P.E. Soister},
  year = {1972},
  doi = {10.3133/ofr72353},
  url = {https://pubs.usgs.gov/publication/ofr72353},
  note = {Source identifier: ofr72353}
}