@misc{indiciaeb57bfda970c5,
  title = {Graphic and mechanical computation of thickness of strata and distance to a stratum},
  author = {J.B. Mertie},
  year = {1922},
  doi = {10.3133/pp129c},
  url = {https://pubs.usgs.gov/publication/pp129C},
  note = {Source identifier: pp129C}
}