@misc{indiciae6bef9240ed4a,
  title = {Teleseismic velocity tomography using the ACH method; theory and application to continental-scale studies},
  author = {J.R. Evans and Ulrich Achauer},
  year = {1993},
  url = {https://pubs.usgs.gov/publication/70186545},
  note = {Source identifier: 70186545}
}