3324 20180103172638.0 OUTRTLK-2018-0001 Janssens, J. De kunst van het zonnewaarnemen 2017 2017-05-03 STCE MIRA Public Observatory (Practical Astronomy Course) jan.janssens@observatoire.be http://www.spaceweather.eu/en/repository/show?id=625 OUTRTLK