@misc{indiciaecc4f815f41e6,
  title = {Preliminary geologic map of the Howardsville Quadrangle, Colorado},
  author = {Robert G. Luedke and Wilbur S. Burbank},
  year = {1975},
  doi = {10.3133/ofr75432},
  url = {https://pubs.usgs.gov/publication/ofr75432},
  note = {Source identifier: ofr75432}
}