@misc{indiciaee9d03cf7aa1d,
  title = {Geology and water-supply potential of the Anoka Sand Plain aquifer, Minnesota},
  author = {J. O. Helgesen and G. F. Lindholm},
  year = {1977},
  url = {https://pubs.usgs.gov/publication/70170909},
  note = {Source identifier: 70170909}
}