@book { PolitikistdiePraxisderWissenschaftvomNotwendigen,
    title = "Politik ist die Praxis der Wissenschaft vom Notwendigen",
    subtitle = "Helmut Ridder (1919-2007)",
    author = "Christoph {Koch}",
    year = "2010",
    publisher = "Meidenbauer",
    address = ", Germany",
    url = "https://www.peterlang.com/document/1136395"
}