Miyahara, H., Masuda, K., Muraki, Y., Kitagawa, H. and Nakamura, T., 2006a, “Variation of solar cyclicity during the Spoerer Minimum”, J. Geophys. Res., 111(A10), A03103. abstract (accessed 12 July 2015)
Yaotiao Jiang and Zhentao Xu, "On the Spörer Minimum", Astrophysics and Space Science, Jan. 1986, Vol. 118, 1-2, pp 159-162. Abstract and link (页面存档备份,存于互联网档案馆) (accessed 12 July 2015)
ucar.edu
windows.ucar.edu
History of Sunspot Observations. [4 February 2009]. (原始内容存档于2009-02-07).
The Spörer Minimum (1420 to 1570), named after the German astronomer Gustav Spörer.
History of Sunspot Observations. [4 February 2009]. (原始内容存档于2009-02-07).
The Spörer Minimum (1420 to 1570), named after the German astronomer Gustav Spörer.
Yaotiao Jiang and Zhentao Xu, "On the Spörer Minimum", Astrophysics and Space Science, Jan. 1986, Vol. 118, 1-2, pp 159-162. Abstract and link (页面存档备份,存于互联网档案馆) (accessed 12 July 2015)