@misc{indiciae0591169192a1,
  title = {Long-term modulation of cosmic rays during solar cycle 21},
  author = {Fenton, A. G. and Fenton, K. B. and Humble, J. E.},
  year = {1985},
  url = {https://ntrs.nasa.gov/citations/19850026695},
  note = {Source identifier: 19850026695}
}