@book { BilingualerErdkundeunterricht,
    title = "Bilingualer Erdkundeunterricht",
    subtitle = "Subjektive didaktische Theorien von Lehrerinnen und Lehrern",
    author = "Britta {Viebrock}",
    year = "2007",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1101703"
}