@misc{indiciaebbfcbc3bd4cb,
  title = {Using geomagnetic indices to forecast the next sunspot maximum},
  author = {Gonzalez, Guillermo and Schatten, Kenneth H.},
  year = {1988},
  url = {https://ntrs.nasa.gov/citations/19880053450},
  note = {Source identifier: 19880053450}
}