@misc{indiciaeb43e1c74a8f5,
  title = {The use of surface geophysical techniques to detect fractures in bedrock; an annotated bibliography},
  author = {Mark R. Lewis and F.P. Haeni},
  year = {1987},
  doi = {10.3133/cir987},
  url = {https://pubs.usgs.gov/publication/cir987},
  note = {Source identifier: cir987}
}