@book { DiehistorischeEntwicklungdereuropischenIntegration,
    title = "Die historische Entwicklung der europäischen Integration",
    author = "Christian {Albers}",
    year = "2002",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783638133241",
    url = "https://www.hausarbeiten.de/document/5458"
}