@book { Mittelstand2008,
    title = "Mittelstand 2008",
    subtitle = "Aktuelle Forschungsbeiträge zu gesellschaftlichen und finanzwirtschaftlichen Herausforderungen",
    author = "Stephan {Schöning} and Jörg {Richter} and Heike {Wetzel} and Dirk {Nissen}",
    year = "2008",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1105188"
}