@book { DiechristlicheGemeinschaftsschuleinBaden,
    title = "Die christliche Gemeinschaftsschule in Baden",
    author = "Johanna {Bäcker}",
    year = "2012",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/978-3-653-01859-2",
    url = "https://www.peterlang.com/document/1046775"
}