@misc{indiciae42ddb733f6a7,
  title = {Preliminary investigations on computational methods for solving the two-point seismic ray-tracing problem in a heterogeneous and isotropic medium},
  author = {J.P. Yang and William Hung Kan Lee},
  year = {1976},
  doi = {10.3133/ofr76707},
  url = {https://pubs.usgs.gov/publication/ofr76707},
  note = {Source identifier: ofr76707}
}