@misc{indiciae5393ec75c9d1,
  title = {Bedrock geologic map of the Springfield 1 degree by 2 degrees Quadrangle, Missouri},
  author = {M.A. Middendorf and Kenneth C. Thomson and G.L. Easson and H.S. Sumner},
  year = {1991},
  doi = {10.3133/i2029},
  url = {https://pubs.usgs.gov/publication/i2029},
  note = {Source identifier: i2029}
}