@misc{indiciae079040628c5a,
  title = {A rapid and accurate contour interpolator},
  author = {O.T. Marsh},
  year = {1960},
  doi = {10.2113/gsecongeo.55.7.1555},
  url = {https://pubs.usgs.gov/publication/70220493},
  note = {Source identifier: 70220493}
}