Sobotka, Michal - Brandt, P. N. - Simon, G. W.
Lifetimes and motions of penumbral grains.
Joint Organization for Solar Observations Annual Report 1998. Tatranská Lomnica: Astronomical Institute of the Slovak Academy of Sciences, 1999 - (Antalová, A.; Balthasar, H.; Kučera, A.), s. 89-90
[Joint Organization for Solar Observations. Potsdam (DE), 22.09.1998-25.09.1998]
http://hdl.handle.net/11104/0022736