@misc{indiciaeadd981beb7c6,
  title = {National Water-Quality Assessment Program - The Rio Grande Valley},
  author = {Sherman R. Ellis},
  year = {1991},
  doi = {10.3133/ofr91160},
  url = {https://pubs.usgs.gov/publication/ofr91160},
  note = {Source identifier: ofr91160}
}