@book { KognitiveReprsentationeninderGrundschule,
    title = "Kognitive Repräsentationen in der Grundschule",
    author = "Barbara {Thies}",
    year = "2010",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/978-3-653-00316-1",
    url = "https://www.peterlang.com/document/1054306"
}