@misc{indiciaebec993a0d04d,
  title = {Instrumental variable methods in structural equation models},
  author = {James Grace},
  year = {2021},
  doi = {10.1111/2041-210x.13600},
  url = {https://pubs.usgs.gov/publication/70223756},
  note = {Source identifier: 70223756}
}