@book { DerIXPdagogischeKongressamEndederDDR,
    title = "Der IX. Pädagogische Kongress am Ende der DDR",
    author = "Heike {Kaack}",
    year = "2016",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/978-3-653-06843-6",
    url = "https://www.peterlang.com/document/1050164"
}