@misc{indiciaec0fa3d3c577f,
  title = {Comparison of a new GIS-based technique and a manual method for determining sinkhole density: An example from Illinois' sinkhole plain},
  author = {J.C. Angel and D.O. Nelson and S.V. Panno},
  year = {2004},
  url = {https://pubs.usgs.gov/publication/70027260},
  note = {Source identifier: 70027260}
}