@misc{indiciae615103d2a523,
  title = {Evidence for deep mantle circulation from global tomography},
  author = {R. D. Van Der Hilst and S. Widiyantoro and E.R. Engdahl},
  year = {1997},
  doi = {10.1038/386578a0},
  url = {https://pubs.usgs.gov/publication/70019882},
  note = {Source identifier: 70019882}
}