@misc{indiciae54d6ebfb2385,
  title = {Substate district, HSA, and PSRO area designations.},
  author = {J R Hammond},
  year = {1976},
  doi = {10.2105/ajph.66.8.788},
  url = {https://pubmed.ncbi.nlm.nih.gov/986777/},
  note = {Source identifier: 986777}
}