@book { DerFilmproduzentLudwigWaldleitner,
    title = "Der Filmproduzent Ludwig Waldleitner",
    author = "Ursula {Kähler}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1103407"
}