@book { DieSteuerunion,
    title = "Die Steuerunion",
    subtitle = "Probleme der Harmonisierung spezifischer Gütersteuern",
    author = " {Anonym}",
    year = "1988",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/b13763",
    url = "https://www.peterlang.com/document/1068343"
}