@online{ timsrc, author = "Ninnemann, Helga AND Häfelinger, Günter", title = "Chemie an der Schwelle des 21. Jahrhunderts, Studium Generale, WiSe 1999/2000, 09.02.2000", publisher = "Universität Tübingen", year = "2000", month = "Feb", day = "09", url = "https://timms.uni-tuebingen.de:443/tp/UT_20000209_001_chemiering_0001", urldate = "2024-11-23" }