@misc{indiciae4e8f969f8c64,
  title = {Geologic and hydrologic aspects of tunneling in the Twin Cities area, Minnesota},
  author = {Ralph F. Norvitch and Matt S. Walton},
  year = {1979},
  doi = {10.3133/i1157},
  url = {https://pubs.usgs.gov/publication/i1157},
  note = {Source identifier: i1157}
}