@online{ timsrc, author = "Kley, Wilhelm AND Werner, Klaus", title = "Streifzug durch die Astronomie, 9. und 10. Stunde", publisher = "Universität Tübingen", year = "2016", month = "Nov", day = "22", url = "https://timms.uni-tuebingen.de:443/tp/UT_20161122_001_rvastro_0001", urldate = "2024-11-27" }