@misc{indiciae32bd8fd0f819,
  title = {The travel-time ellipse: An approximate zone of transport},
  author = {J.E. Almendinger},
  year = {1994},
  doi = {10.1016/0022-1694(94)90135-x},
  url = {https://pubs.usgs.gov/publication/70017653},
  note = {Source identifier: 70017653}
}