@book { DreiseitigeVereinbarungen,
    title = "Dreiseitige Vereinbarungen",
    author = "Kristina {Ruch}",
    year = "2010",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/978-3-653-00008-5",
    url = "https://www.peterlang.com/document/1044222"
}