@book { Stadtmarketing2002,
    title = "Stadtmarketing 2002",
    author = "Oliver {Plischek}",
    year = "2003",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832464783",
    url = "https://m.diplom.de/document/221897"
}