太陽活動と経済について☀黒点の増減と周期性　


https://www.kwasan.kyoto-u.ac.jp/hosizora/astron/astron7/astron7_P27-31.pdf

https://toyokeizai.net/articles/amp/335644?display=b&;amp_event=read-body

https://search.yahoo.co.jp/amp/s/pixy10.org/archives/605799.html%3Famp%3D1%26usqp%3Dmq331AQQKAGYAaDSoY_Nw_qnabABIA%253D%253D