@misc{indiciae50f81751b687,
  title = {Geologic map of the Poncha Springs NE quadrangle, Chaffee County, Colorado},
  author = {R. E. Van Alstine and D. C. Cox},
  year = {1966},
  doi = {10.3133/ofr66145},
  url = {https://pubs.usgs.gov/publication/ofr66145},
  note = {Source identifier: ofr66145}
}