@online{
   timsrc,
   author = "Werner, Klaus",
   title = "Vorlesung Einführung in die Astronomie I, 16. Stunde",
   publisher = "Universität Tübingen",
   year = "2009",
   month = "Feb",
   day = "11",
   url = "https://timms.uni-tuebingen.de:443/tp/UT_20090211_001_astro1_0001",
   urldate = "2024-04-20"
}