History of Sunspot Research and Forecast of the Maximum of Solar Cycle 25

[31] Dreyer J. L. E.(2013)Inconsistency of the Wolf sunspot number series around 1848 Astron. Astrophys. 559 A28-19

[32] Edgecomb D. W.(2013)The sunspot cycle revisited J. Phys.: Conf. Ser. 440 012042-2985

[33] Engvold O.(1928)The mean period of the sun-spots Pop. Astron. 36 537-386

[34] Zirker J. B.(1890)Scheiner and the solar spots Observatory 13 111-236

[35] Giudice F.(1902)The invention of the telescope Observatory 25 436-222

[36] Hathaway D. H.(1903)The family of Horrebow Observatory 26 420-64

[37] Hayakawa H.(2013)L’origine du télescope (II) Ciel 75 66-112

[38] Clette F.(2020)Uncertainty quantification in sunspot counts Astrophys. J. 886 7-320

[39] Horaguchi T.(2019)Visualization of the challenges and limitations of the longterm sunspot number record Nature Astron. 3 205-96

[40] Iju T.(1961)A very unusual flare on November 15, 1960 Publ. Astron. Soc. Jpn. 13 129-96

[31] Dreyer J. L. E.(2013)Inconsistency of the Wolf sunspot number series around 1848 Astron. Astrophys. 559 A28-19

[32] Edgecomb D. W.(2013)The sunspot cycle revisited J. Phys.: Conf. Ser. 440 012042-2985

[33] Engvold O.(1928)The mean period of the sun-spots Pop. Astron. 36 537-386

[34] Zirker J. B.(1890)Scheiner and the solar spots Observatory 13 111-236

[35] Giudice F.(1902)The invention of the telescope Observatory 25 436-222

[36] Hathaway D. H.(1903)The family of Horrebow Observatory 26 420-64

[37] Hayakawa H.(2013)L’origine du télescope (II) Ciel 75 66-112

[38] Clette F.(2020)Uncertainty quantification in sunspot counts Astrophys. J. 886 7-320

[39] Horaguchi T.(2019)Visualization of the challenges and limitations of the longterm sunspot number record Nature Astron. 3 205-96

[40] Iju T.(1961)A very unusual flare on November 15, 1960 Publ. Astron. Soc. Jpn. 13 129-96