@book { WasistPolitik,
    title = "Was ist Politik?",
    author = "Oliver {Krüger}",
    year = "2003",
    publisher = "GRIN Verlag",
    address = "München, Germany",
    doi = "10.3239/9783638203746",
    url = "https://www.hausarbeiten.de/document/15183"
}