@book { QuErDenken,
    title = "QuErDenken!",
    subtitle = "Leben und Werk Ludwig von Bertalanffys",
    author = "Wolfgang {Hofkirchner}",
    year = "2005",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1097174"
}