@online{ timsrc, author = "Werner, Klaus", title = "Vorlesung Einführung in die Astronomie II, 2. Stunde", publisher = "Universität Tübingen", year = "2009", month = "Apr", day = "29", url = "https://timms.uni-tuebingen.de:443/tp/UT_20090429_001_astro2_0001", urldate = "2024-03-29" }