@misc{indiciae1a32a5afaaae,
  title = {Nickel-gold deposit near Mount Vernon, Skagit County, Washington},
  author = {S. W. Hobbs and W. T. Pecora},
  year = {1941},
  doi = {10.3133/b931d},
  url = {https://pubs.usgs.gov/publication/b931D},
  note = {Source identifier: b931D}
}