Begivenheter
Referanser
- ^ Mekhaldi, Florian; Muscheler, Raimund; Adolphi, Florian; Aldahan, Ala; Beer, Jürg; McConnell, Joseph R.; Possnert, Göran; Sigl, Michael; Svensson, Anders; Synal, Hans-Arno; Welten, Kees C. (26. oktober 2015). «Multiradionuclide evidence for the solar origin of the cosmic-ray events of AD 774/5 and 993/4». Nature Communications. 6 (1): 8611. doi:10.1038/ncomms9611.