@misc{indiciae212d065c2e47,
  title = {Ground-water problems in the United States},
  author = {C. G. Paulsen},
  year = {1949},
  doi = {10.3133/ofr4996},
  url = {https://pubs.usgs.gov/publication/ofr4996},
  note = {Source identifier: ofr4996}
}