@misc{indiciaea61087274a1f,
  title = {Geologic map of the Mt. Harvard quadrangle, Gunnison and Chaffee Counties, Colorado},
  author = {M. R. Brock and Fred Barker},
  year = {1966},
  doi = {10.3133/ofr669},
  url = {https://pubs.usgs.gov/publication/ofr669},
  note = {Source identifier: ofr669}
}