@online{
   timsrc,
   author = "Markl, Gregor",
   title = "Vorlesung Einführung in die Petrologie, 6. Stunde",
   publisher = "Universität Tübingen",
   year = "2005",
   month = "May",
   day = "18",
   url = "https://timms.uni-tuebingen.de:443/tp/UT_20050518_001_petrol_0001",
   urldate = "2024-05-17"
}