@misc{indiciae49fbf47caaef,
  title = {On comparing helioseismic two-dimensional inversion methods},
  author = {Schou, J. and Christensen-Dalsgaard, J. and Thompson, M. J.},
  year = {1994},
  url = {https://ntrs.nasa.gov/citations/19950038096},
  note = {Source identifier: 19950038096}
}