@online{ timsrc, author = "Werner, Klaus", title = "Vorlesung Einführung in die Astronomie II, 7. Stunde", publisher = "Universität Tübingen", year = "2009", month = "Jun", day = "10", url = "https://timms.uni-tuebingen.de:443/tp/UT_20090610_001_astro2_0001", urldate = "2024-11-21" }