@online{ timsrc, author = "Grammig, Joachim", title = "Lecture Quantitative Methods in Economics and Business Administration, 8. Lesson", publisher = "Universität Tübingen", year = "2025", month = "Nov", day = "03", url = "https://timms.uni-tuebingen.de:443/tp/UT_20251103_002_ws2526quantmethwiwi_0001", urldate = "2025-11-11" }