@book { DieSonderschulealsArmenschule,
    title = "Die Sonderschule als Armenschule",
    author = "Dagmar {Hänsel} and Hans-Joachim {Schwager}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Lausanne, Switzerland",
    url = "https://www.peterlang.com/document/1096886"
}