@book { DieUmsatzsteuerNachschaunach27bUStG,
    title = "Die Umsatzsteuer-Nachschau nach § 27b UStG",
    author = "Heike {Rüping}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1105443"
}