Historical sunspot observations: A review
Advances in space research ; 40 , 7 ; 929-941
2007
Article (Journal)
Unknown
Sunspot group tilt angle measurements from historical observations
Online Contents | 2016
|High-resolution sunspot observations
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|High-resolution sunspot observations
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|The structure of sunspot umbras. i - observations.
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|British Library Conference Proceedings | 2002
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