@misc{indiciae561693cc23ff,
  title = {Utilization of mull (forest humus layer) in geochemical exploration in the Empire district, Clear Creek County, Colorado},
  author = {Gary C. Curtin and H. W. Lakin and A.E. Hubert and E. L. Mosier and K. C. Watts},
  year = {1971},
  doi = {10.3133/b1278b},
  url = {https://pubs.usgs.gov/publication/b1278B},
  note = {Source identifier: b1278B}
}