@online{ timsrc, author = "Grammig, Joachim", title = "Lecture Quantitative Methods in Economics and Business Administration, 1. Lesson", publisher = "Universität Tübingen", year = "2025", month = "Oct", day = "13", url = "https://timms.uni-tuebingen.de:443/tp/UT_20251013_001_ws2526quantmethwiwi_0001", urldate = "2025-11-12" }