@misc{indiciaeac8912a17995,
  title = {Using dynamo theory to predict the sunspot number during solar cycle 21},
  author = {Schatten, K. H. and Scherrer, P. H. and Svalgaard, L. and Wilcox, J. M.},
  year = {1978},
  url = {https://ntrs.nasa.gov/citations/19780053157},
  note = {Source identifier: 19780053157}
}