@misc{indiciae13240161b725,
  title = {Geology-based planning and the aggregate industry - Perspectives from opposite sides of the globe},
  author = {A.W. Stephens and W. H. Langer},
  year = {2006},
  url = {https://pubs.usgs.gov/publication/70030426},
  note = {Source identifier: 70030426}
}