@misc{indiciae33a3919f824c,
  title = {Long-term forecasting of solar activity},
  author = {Zhen-Tao, X. and Ai-Di, Z. and Yan-Lin, M. and Quan-Shi, G.},
  year = {1979},
  url = {https://ntrs.nasa.gov/citations/19800010202},
  note = {Source identifier: 19800010202}
}