@article{dziewoski1981,
  title={Preliminary reference Earth model},
  author={Adam M. Dziewoński and Don L. Anderson},
  year={1981},
  journal={Physics of The Earth and Planetary Interiors},
  doi={10.1016/0031-9201(81)90046-7},
  url={https://doi.org/10.1016/0031-9201(81)90046-7}
}