@misc{indiciae6bd94984860a,
  title = {Aerial gamma-ray color contour maps of regional surface concentrations of potassium, uranium, thorium and composite-color maps of uranium, potassium, thorium, and their ratios in New Mexico},
  author = {J. S. Duval},
  year = {1989},
  doi = {10.3133/gp980},
  url = {https://pubs.usgs.gov/publication/gp980},
  note = {Source identifier: gp980}
}