@misc{indiciaea0a5d3fb1b97,
  title = {A study of alternative schemes for extrapolation of secular variation at observatories},
  author = {L.R. Alldredge},
  year = {1976},
  doi = {10.1016/0031-9201(76)90015-7},
  url = {https://pubs.usgs.gov/publication/70010426},
  note = {Source identifier: 70010426}
}