@online{ timsrc, author = "Kley, Wilhelm AND Werner, Klaus", title = "Streifzug durch die Astronomie, 5. und 6. Stunde", publisher = "Universität Tübingen", year = "2016", month = "Nov", day = "08", url = "https://timms.uni-tuebingen.de:443/tp/UT_20161108_001_rvastro_0001", urldate = "2024-04-25" }